Population Concepts and Growth Dynamics Practice Questions — JAMB UTME

Question 1Question →

A demographic survey of a municipality in West Africa recorded a population structure consisting of $12{}000$ children aged under 15 years, $20{}000$ adults aged 15–64 years, and $4{}000$ elderly individuals aged 65 years and above. What is the total dependency ratio of this municipality?

80.0\%

125.0\%

44.4\%

60.0\%

Show answer & explanation

Answer: $80.0\%$

Answer

The total dependency ratio of the municipality is

80.0\%

.

The total dependency ratio measures the pressure on the productive population by comparing non-working age groups (under 15 and 65+) to the working-age group (15–64). With

16{}000

total dependents and

20{}000

working-age individuals, the ratio is

(16{}000 / 20{}000) \times 100 = 80.0\%

.

Step-by-Step Solution

1

Calculate the total dependent population

Dependent population = Youth (under 15) + Elderly (65 and above) =

12{}000 + 4{}000 = 16{}000

Dependents include all individuals outside the economically active age range of 15–64 years.

2

Identify the working-age population

Working-age population =

20{}000

The population aged 15–64 years represents the economically active group.

3

Apply the total dependency ratio formula

\text{Dependency Ratio} = \left( \frac{16{}000}{20{}000} \right) \times 100 = 80.0\%

The formula for Dependency Ratio is (Total Dependents / Working-Age Population) * 100.

Key Concept

Dependency Ratio Calculation

Question 2Question →

Match each stage of the Demographic Transition Model on the left with its corresponding birth and death rate characteristic on the right.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Stage 1 (High Stationary) pairs with high birth and high death rates; Stage 2 (Early Expanding) pairs with high birth rate and rapidly falling death rate; Stage 3 (Late Expanding) pairs with falling birth rate and low death rate; Stage 4 (Low Stationary) pairs with low birth rate and low death rate.

Each stage of the Demographic Transition Model represents a specific evolutionary phase of birth and death rates as a society undergoes economic and social development. Stage 1 pairs high births with high deaths (low growth), Stage 2 pairs high births with plummeting deaths (rapid expansion), Stage 3 pairs dropping births with low deaths (slowing expansion), and Stage 4 pairs low births with low deaths (stationary equilibrium).

Step-by-Step Solution

1

Identify the demographic conditions of Stage 1.

High birth rates and high death rates cancel each other out, giving a low, fluctuating population.

Early agrarian societies faced high infant mortality and disease.

2

Identify the demographic conditions of Stage 2.

Birth rates stay high while death rates plunge, yielding maximum natural increase.

Improvements in healthcare, diet, and sanitation dramatically lower mortality before fertility norms change.

3

Identify the demographic conditions of Stage 3.

Birth rates fall noticeably while death rates remain low.

Socio-economic development, female education, and urban lifestyle reduce family size preference.

4

Identify the demographic conditions of Stage 4.

Both birth and death rates level off at low values.

Industrialized societies achieve demographic equilibrium with low growth rates.

Key Concept

Demographic Transition Model Stages and Population Growth Dynamics

Question 3Question →

During a demographic study of a developing nation, researchers recorded a rapid decline in the crude death rate due to improved medical services, while the crude birth rate remained consistently high. Which stage of the Demographic Transition Model does this scenario describe, and what is its effect on population growth?

Stage 1 (High Stationary), producing a stagnant population with high fluctuation.

Stage 2 (Early Expanding), producing rapid population growth due to a high rate of natural increase.

Stage 3 (Late Expanding), producing moderate growth driven mainly by rural push factors.

Stage 4 (Low Stationary), producing a declining population due to an inverted dependency ratio.

Show answer & explanation

Answer: Stage 2 (Early Expanding), producing rapid population growth due to a high rate of natural increase.

Answer

Stage 2 (Early Expanding), producing rapid population growth due to a high rate of natural increase.

Stage 2 (Early Expanding) of the Demographic Transition Model is defined by a significant drop in mortality rates—brought about by improvements in public health, healthcare, and food supply—while birth rates remain high. This wide divergence between births and deaths creates a high rate of natural increase, causing rapid population growth.

Step-by-Step Solution

1

Analyze the given demographic indicators

Crude death rate is falling rapidly while crude birth rate remains high.

Identifying birth and death rate trends is essential for determining the correct Demographic Transition Model stage.

2

Map the birth and death rate trends to the Demographic Transition Model stages

The combination of high birth rate and rapidly falling death rate corresponds to Stage 2 (Early Expanding).

Stage 2 occurs when sanitation and healthcare lower mortality before socio-economic changes lower fertility.

3

Determine the impact on overall population growth

The wide gap between high birth rates and low death rates yields a high rate of natural increase (CBR - CDR).

Natural increase measures population growth excluding net migration.

Key Concept

Demographic Transition Model - Stage 2 (Early Expanding Stage)

Question 4Question →

An urbanizing district in West Africa with an estimated mid-year population of $500{}000$ recorded $16{}000$ live births, $6{}000$ deaths, $3{}000$ in-migrants, and $1{}000$ out-migrants within a single year. What is the annual net population growth rate of this district expressed as a percentage?

Show answer & explanation

Answer: 2.4

Answer

The annual net population growth rate of the district is

2.4\%

.

Total net population change combines natural increase (

16{}000 \text{ births} - 6{}000 \text{ deaths} = 10{}000

) and net migration (

3{}000 \text{ in-migrants} - 1{}000 \text{ out-migrants} = 2{}000

), giving a total increase of

12{}000

. Expressing

12{}000

as a percentage of the total mid-year population of

500{}000

yields

\frac{12{}000}{500{}000} \times 100 = 2.4\%

.

Step-by-Step Solution

1

Calculate the natural increase in population.

Natural Increase =

16{}000 - 6{}000 = 10{}000

individuals.

Natural increase represents the population growth resulting strictly from the surplus of births over deaths.

2

Calculate the net migration for the year.

Net Migration =

3{}000 - 1{}000 = 2{}000

individuals.

Net migration is the net balance between incoming migrants (immigration) and outgoing migrants (emigration).

3

Determine the total annual population gain.

Total Population Addition =

10{}000 + 2{}000 = 12{}000

individuals.

Overall demographic growth incorporates both natural increase and net spatial mobility.

4

Compute the net growth rate percentage.

Annual Growth Rate =

\left(\frac{12{}000}{500{}000}\right) \times 100\% = 2.4\%

.

Dividing total net gain by the base mid-year population and scaling by 100 converts absolute growth into an annual percentage rate.

Key Concept

Total Net Population Growth Rate (Natural Increase + Net Migration)

Question 5Question →

A certain district in West Africa recorded 1,200 live births in a given year within a mid-year population of 50,000. Calculate the Crude Birth Rate (CBR) per 1,000 population for this district.

Show answer & explanation

Answer: 24

Answer

24 per 1,000 population

The correct rate of 24 per 1,000 is derived by dividing total live births (1,200) by total mid-year population (50,000) and scaling the result per 1,000 individuals.

Step-by-Step Solution

1

Identify the given demographic parameters from the problem stem

Total live births = 1,200; Mid-year population = 50,000

These inputs are required for determining crude birth rate.

2

Apply the Crude Birth Rate formula

CBR = (1,200 / 50,000) * 1,000

Crude Birth Rate standardizes births per 1,000 members of a population per year.

3

Calculate the final numeric value

CBR = 24

Dividing 1,200 by 50,000 yields 0.024, which multiplied by 1,000 equals 24.

Key Concept

Crude Birth Rate (CBR) Calculation

Question 6Question →

A community in Nigeria has a recorded population distribution comprising $15{}000$ individuals aged under $15$ years, $40{}000$ individuals aged $15\text{--}64$ years, and $5{}000$ individuals aged $65$ years and above.

What is the demographic dependency ratio for this community?

50%

200%

33.3%

37.5%

Show answer & explanation

Answer: 50%

Answer

50%

The dependency ratio measures the number of dependents (aged 0–14 and 65+) relative to the working-age population (aged 15–64). Here, the total dependent population is

15{}000 + 5{}000 = 20{}000

. Dividing

20{}000

by the working-age population of

40{}000

gives

0.5

, which equals

50\%

.

Step-by-Step Solution

1

Calculate the total dependent population

15{}000 + 5{}000 = 20{}000

Dependents consist of individuals under 15 years old and individuals aged 65 years and above.

2

Identify the working-age (independent) population

40{}000

The working-age population comprises individuals between 15 and 64 years of age.

3

Apply the Dependency Ratio formula

\text{Dependency Ratio} = \left( \frac{20{}000}{40{}000} \right) \times 100 = 50\%

The formula divides the dependent population by the working-age population and expresses it as a percentage.

Key Concept

Demographic Dependency Ratio

Estimated Time:1m 0s

Question 7Question →

In a given administrative zone in West Africa with an estimated mid-year population of $250{}000$ , a demographic survey recorded $7{}500$ live births and $2{}500$ deaths during a single calendar year. In the same year, records showed that $1{}250$ individuals moved permanently into the zone while $750$ individuals emigrated out. Based on these demographic statistics, what is the annual total population growth rate of the zone expressed as a percentage?

Show answer & explanation

Answer: 2.2

Answer

The annual total population growth rate of the administrative zone is

2.2\%

.

The total population growth rate integrates natural growth (live births minus deaths) and net migration balance (immigrants minus emigrants). With

5{}000

net natural additions (

2.0\%

) and

500

net migration additions (

0.2\%

), the total annual growth rate equals

2.2\%

.

Step-by-Step Solution

1

Determine the natural population change

Natural Increase = Births - Deaths =

7{}500 - 2{}500 = 5{}000

Natural population change isolates natural demographic events prior to factoring in net spatial mobility.

2

Calculate the Rate of Natural Increase (RNI) as a percentage

\text{RNI} = \left(\frac{5{}000}{250{}000}\right) \times 100\% = 2.0\%

Expressing natural increase relative to the mid-year population standardized as a percentage yields the natural growth rate.

3

Determine the net migration change and Net Migration Rate (NMR)

Net Migration = Immigrants - Emigrants =

1{}250 - 750 = 500

;

\text{NMR} = \left(\frac{500}{250{}000}\right) \times 100\% = 0.2\%

Net migration accounts for population gains and losses resulting from external spatial movements.

4

Sum the Rate of Natural Increase and Net Migration Rate

\text{Total Population Growth Rate} = 2.0\% + 0.2\% = 2.2\%

Overall population growth rate is the sum of natural population growth rate and net migration rate.

Key Concept

Calculation of Total Population Growth Rate incorporating Natural Increase and Net Migration

Question 8Question →

A demographic survey of a developing country records the following age structure: $18{}000{}000$ individuals under 15 years of age, $2{}000{}000$ individuals aged 65 years and above, and $30{}000{}000$ individuals in the economically active age bracket of 15–64 years. Based on these data, what is the total dependency ratio of the country?

66.7\%

150.0\%

40.0\%

60.0\%

Show answer & explanation

Answer: $66.7\%$

Answer

The total dependency ratio of the country is

66.7\%

.

The dependency ratio measures the number of dependents (aged 0–14 and 65+) relative to the working-age population (aged 15��64). Summing the non-working population (

18{}000{}000 + 2{}000{}000 = 20{}000{}000

) and dividing by the working population (

30{}000{}000

) gives

\frac{20{}000{}000}{30{}000{}000} \times 100 = 66.7\%

.

Step-by-Step Solution

1

Identify the total dependent population (youth population under 15 years + elderly population 65 years and above).

Total Dependents =

18{}000{}000 + 2{}000{}000 = 20{}000{}000

.

Both age groups under 15 and 65+ constitute the economically non-working dependent population.

2

Identify the economically active (working-age) population (aged 15 to 64 years).

Working-age population =

30{}000{}000

.

The dependency ratio measures the burden carried by the productive age group.

3

Apply the standard formula for Total Dependency Ratio:

\text{Dependency Ratio} = \frac{\text{Total Dependents}}{\text{Working Population}} \times 100

.

\text{Dependency Ratio} = \frac{20{}000{}000}{30{}000{}000} \times 100 = 66.67\% \approx 66.7\%

.

This yields the correct percentage of dependents supported per 100 working-age individuals.

Key Concept

Demographic Dependency Ratio

Question 9Question →

In demographic analysis, which of the following mathematical expressions correctly defines the dependency ratio of a population?

\frac{\text{Population aged } <15 + \text{Population aged } \ge 65}{\text{Population aged } 15\text{--}64} \times 100

\frac{\text{Population aged } 15\text{--}64}{\text{Population aged } <15 + \text{Population aged } \ge 65} \times 100

\frac{\text{Crude Birth Rate} - \text{Crude Death Rate}}{\text{Total Population}} \times 1000

\frac{\text{Population aged } <15}{\text{Population aged } \ge 65} \times 100

Show answer & explanation

Answer: $\frac{\text{Population aged } <15 + \text{Population aged } \ge 65}{\text{Population aged } 15\text{--}64} \times 100$

Answer

The dependency ratio is correctly calculated as

\frac{\text{Population aged } <15 + \text{Population aged } \ge 65}{\text{Population aged } 15\text{--}64} \times 100

.

The dependency ratio measures the economic burden on the productive population by comparing dependents (children under 15 and elderly individuals aged 65 and above) to the working-age population (aged 15 to 64), expressed per 100 working individuals.

Step-by-Step Solution

1

Identify the dependent age groups within a population structure.

The dependent population consists of children under 15 years old and elderly individuals aged 65 and above.

These groups are generally considered economically inactive or dependent on others.

2

Identify the economically active (working-age) population group.

The working-age group spans individuals aged 15 to 64 years.

This cohort generates the economic output to support themselves and dependents.

3

Formulate the dependency ratio.

Divide the total dependents by the working-age population and multiply by 100 to express as a percentage.

This yields the number of dependents per 100 working-age individuals.

Key Concept

Dependency Ratio Calculation

Question 10Question →

According to Thomas Malthus' theory on population dynamics, human population tends to increase exponentially (geometrically) while food supply increases arithmetically. Which of the following represents a 'preventive check' to population growth within Malthusian theory?

Moral restraint and delayed marriage

Outbreaks of severe famine and epidemic diseases

Technological advancements in food production systems

Mass displacement driven by severe environmental degradation

Show answer & explanation

Answer: Moral restraint and delayed marriage

Answer

Moral restraint and delayed marriage represent a preventive check to population growth according to Malthusian theory.

Moral restraint and delayed marriage are classic examples of preventive checks in Malthusian demographic theory. They involve conscious human decisions that reduce fertility and lower the overall birth rate before resource shortages trigger catastrophic mortality spikes.

Step-by-Step Solution

1

Examine the core components of Malthusian population growth theory.

Thomas Malthus posited that unchecked population grows exponentially (

1, 2, 4, 8, 16...

) while food production increases arithmetically (

1, 2, 3, 4, 5...

), eventually leading to a resource crisis.

Establishing the imbalance between demographic growth and resource supply explains why population checks become necessary.

2

Distinguish between the two categories of population checks identified by Malthus.

Preventive checks reduce fertility through deliberate human action (lowering crude birth rate), whereas positive checks shorten life expectancy through crisis events (raising crude death rate).

Recognizing the difference between birth-reducing preventive factors and death-increasing positive factors is essential for correct classification.

3

Identify the option that constitutes a voluntary limitation of fertility.

Moral restraint and postponing marriage directly reduce birth rates voluntarily, fitting the exact definition of a Malthusian preventive check.

This is the primary voluntary mechanism proposed by Malthus to avert overpopulation before catastrophic positive checks occur.

Key Concept

Malthusian Population Theory (Preventive vs. Positive Checks)

Question 11Question →

Match each population theory, model stage, or demographic concept on the left with its corresponding characteristic description or theoretical premise on the right.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Demographic Transition Model (Stage 4) matches the condition where birth and death rates stabilize at low levels with negligible natural growth; Malthusian Population Theory matches the concept of geometric population expansion versus arithmetic food growth; Optimum Population Concept matches the population size yielding maximum per capita economic output; Boserupian Theory matches the premise that population pressure stimulates agricultural and technological innovation.

Each demographic theory and model stage accurately aligns with its foundational assumption: Stage 4 of the Demographic Transition Model features low birth/death equilibrium; Malthus emphasizes geometric vs arithmetic growth rates; Optimum population targets peak per capita economic output; Boserup highlights population growth as a direct catalyst for technological innovation.

Step-by-Step Solution

1

Analyze the characteristic features of Stage 4 of the Demographic Transition Model.

Identify that birth and death rates are low, equalized, and produce a stationary or aging population structure.

Stage 4 represents a post-industrial demographic equilibrium where socioeconomic development lowers fertility to match low mortality.

2

Examine the mathematical core of Malthusian Population Theory.

Match Malthus with the geometric rate of demographic increase versus arithmetic growth of agricultural yields.

Malthusian theory rests on the fundamental imbalance between population growth velocity and food production limits.

3

Define the economic criteria of the Optimum Population concept.

Associate optimum population with peak per capita productivity given resource and technological constraints.

Underpopulation or overpopulation yields lower per capita income, whereas the optimum balances labor force size with capital resources for maximum economic returns.

4

Evaluate the counter-perspective of Boserupian demographic theory.

Link Ester Boserup's model to technological innovation induced directly by population density and food demand.

Boserup proposed that population growth is an independent variable forcing societies to innovate land-use practices and agricultural technologies.

Key Concept

Demographic Theories, Transition Stages, and Population-Resource Models

Estimated Time:2m 0s

Question 12Question →

In a demographic survey of a municipality in Nigeria, the total population was recorded as $120{}000$ . The survey revealed that $42\%$ of the population is under $15$ years of age, and $6\%$ is aged $65$ years and above. Calculate the total dependency ratio of the municipality (expressed as a percentage rounded to one decimal place).

Show answer & explanation

Answer: 92.3

Answer

The total dependency ratio of the municipality is 92.3%.

The total dependency ratio expresses the number of dependents (youth under 15 and elderly 65 and over) relative to the working-age population (15 to 64). Here, dependents constitute 48% (42% + 6%) of the population, leaving 52% (100% - 48%) in the working-age cohort. Dividing the dependents by the working age group gives (48 / 52) × 100 = 92.3%.

Step-by-Step Solution

1

Calculate the dependent population percentage and working-age population percentage.

Dependent population percentage = 42% + 6% = 48%; Working-age population percentage = 100% - 48% = 52%.

Demographic dependents consist of youth under 15 years and elderly aged 65 years and above, while the active labor force consists of age groups between 15 and 64 years.

2

Substitute the cohort percentages into the standard dependency ratio formula.

Dependency Ratio = (48 / 52) × 100

The dependency ratio measures the economic burden carried by the productive segment of the population per 100 working-age individuals.

3

Compute the numerical value and round to one decimal place.

92.3%

Dividing 48 by 52 yields approximately 0.92307, which converts to 92.3%.

Key Concept

Dependency Ratio Calculation

Question 13Question →

Demographic analysis relies on precise definitions of population metrics and growth dynamics. Match each population concept on the left with its corresponding definition or characteristic feature on the right.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Crude Birth Rate matches the annual live births per 1,000 mid-year population; Rate of Natural Increase matches the birth rate minus death rate growth percentage; Dependency Ratio matches the ratio of dependent age groups to the working-age population; Stage 2 of the Demographic Transition Model matches high birth rates with rapidly falling death rates.

Each demographic concept is matched strictly according to standard demographic definitions: Crude Birth Rate measures live births per 1,000 people; Rate of Natural Increase measures the excess of birth rate over death rate expressed as a percentage without migration; Dependency Ratio compares young and elderly dependents to the 15–64 working population; and Stage 2 of the Demographic Transition Model features high birth rates alongside rapidly declining death rates.

Step-by-Step Solution

1

Identify the standard demographic formula and unit measure for Crude Birth Rate.

Crude Birth Rate measures live births per 1,000 mid-year population.

It measures fertility relative to total population size without age adjustment.

2

Differentiate Rate of Natural Increase from total population growth rate.

Rate of Natural Increase equals (CBR - CDR) / 10, measuring growth without net migration.

Natural increase considers only biological growth factors (births and deaths).

3

Analyze the structural age cohorts that form the Dependency Ratio.

Dependency ratio divides dependent cohorts (aged 0–14 and 65+) by the working cohort (aged 15–64).

It assesses the economic support burdens placed on productive age groups.

4

Examine the mortality and fertility trends associated with Stage 2 of the Demographic Transition Model.

Stage 2 is defined by high birth rates and fast-dropping death rates.

Improvements in healthcare lower mortality quickly while cultural birth preferences persist.

Key Concept

Demographic Concepts and Population Growth Metrics

Question 14Question →

Match each population growth concept or metric on the left with its corresponding analytical definition or operational condition on the right.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Population Momentum matches the demographic phenomenon of continued growth due to a broad young age-structure base; Demographic Dividend matches the economic growth potential from a favorable decline in dependency ratio; Net Reproduction Rate (

NRR = 1.0

) matches the replacement equilibrium accounting for female survival to childbearing age; Doubling Time matches the calculation of

70

divided by the annual growth rate percentage.

Each demographic concept is matched strictly to its operational definition: Population Momentum explains growth inertia from age-structure base; Demographic Dividend defines economic opportunity from reduced dependency ratios; Net Reproduction Rate (

NRR=1.0

) specifies generational female replacement considering survival rates; and Doubling Time defines exponential growth duration via the Rule of 70.

Step-by-Step Solution

1

Analyze Population Momentum

Identify that momentum stems from youth-heavy age structures where historical high fertility maintains growth despite current replacement fertility.

Structural inertia keeps birth counts high even when individual fertility rates drop.

2

Analyze Demographic Dividend

Identify that this dividend occurs during Demographic Transition Stage 3 when child dependency drops while elder dependency remains low.

Economic productivity increases when a higher proportion of the population is in active labor force cohorts.

3

Analyze Net Reproduction Rate (

NRR = 1.0

)

Distinguish NRR from Total Fertility Rate (TFR) by recognizing that NRR explicitly incorporates female mortality risk before reaching reproductive age.

NRR measures daughter survival rates to establish true generational population replacement.

4

Analyze Doubling Time (Rule of 70)

Link doubling time estimation to exponential growth principles where doubling period equals

70 / r

(where

r

is percentage growth rate).

Standard demographic calculation derived from the natural logarithm approximation

\ln(2) \approx 0.693

.

Key Concept

Demographic Concepts and Population Growth Metrics

Question 15Question →

In a semi-urban local government area in Kano State, Nigeria, the total age dependency ratio is recorded as $80\%$ . If the population of children (aged $0-14$ years) is $90{}000$ and the population of elderly persons (aged $65$ years and above) is $18{}000$ , what is the total number of economically active individuals (aged $15-64$ years) in this local government area?

Show answer & explanation

Answer: 135000

Answer

The total number of economically active individuals (aged 15–64 years) is

135{}000

.

The total age dependency ratio is defined as the ratio of dependents (people aged

0-14

and

65+

) to the working-age population (aged

15-64

), multiplied by

100

. Summing the youth (

90{}000

) and elderly (

18{}000

) yields

108{}000

total dependents. Dividing

108{}000

by the dependency ratio (

0.80

) gives exactly

135{}000

economically active individuals.

Step-by-Step Solution

1

Calculate the total dependent population

108{}000

dependents

The dependent population consists of youth under 15 years (

90{}000

) and elderly individuals aged 65 years and over (

18{}000

).

2

Set up the age dependency ratio equation

80 = \frac{108{}000}{\text{Pop}_{15-64}} \times 100

The dependency ratio measures the relationship between the dependent cohort and the working-age cohort (

15-64

years).

3

Rearrange the equation to solve for the working-age population

\text{Pop}_{15-64} = \frac{108{}000 \times 100}{80} = 135{}000

Dividing the total dependent population by the dependency ratio expressed as a decimal (

0.80

) yields the total economically active population.

Key Concept

Age Dependency Ratio and Cohort Analysis

Estimated Time:2m 0s

Question 16Question →

In a baseline demographic survey of an agricultural district in West Africa, $35\%$ of the population is under 15 years of age, $60\%$ is between 15 and 64 years of age, and $5\%$ is 65 years of age or older. What is the total dependency ratio of this district?

40.0\%

58.3\%

66.7\%

150.0\%

Show answer & explanation

Answer: $66.7\%$

Answer

The total dependency ratio of the district is

66.7\%

.

To calculate the total dependency ratio, sum the young dependents (

35\%

) and elderly dependents (

5\%

) to get a total dependent population of

40\%

. Divide this sum by the working-age population (

60\%

) and multiply by 100 to get

66.7\%

.

Step-by-Step Solution

1

Determine the total percentage of dependents in the population.

Dependent Population =

35\% \text{ (under 15)} + 5\% \text{ (65 and older)} = 40\%

.

The dependent population consists of children under 15 years and elderly adults 65 years and older.

2

Identify the economically active (working-age) population percentage.

Working-Age Population =

60\%

.

The economically active cohort comprises individuals aged 15 to 64 years.

3

Apply the total dependency ratio formula.

\text{Dependency Ratio} = \frac{\text{Dependent Population}}{\text{Working-Age Population}} \times 100 = \frac{40}{60} \times 100 = 66.7\%

The ratio measures the economic burden borne by the working-age population to support non-working dependents.

Key Concept

Total Dependency Ratio Calculation

Question 17Question →

Match each population concept or growth index on the left with its corresponding demographic definition or structural relationship on the right.

Click a left item, then click its matching right item

Show answer & explanation

Answer

The correct pairings match Crude Birth Rate with live births per 1,000 mid-year population; Rate of Natural Increase with net annual percentage growth from birth surplus over deaths; Total Dependency Ratio with the ratio of non-working dependent age groups to the working-age group; and Population Momentum with sustained population growth driven by a high proportion of young people entering reproductive age.

Each demographic concept is matched strictly with its standard analytical definition used in population geography.

Step-by-Step Solution

1

Analyze Crude Birth Rate

Matched with live births per 1,000 mid-year population.

CBR measures crude natality per standardized thousand-person unit.

2

Analyze Rate of Natural Increase

Matched with net percentage growth driven by birth surplus over deaths.

RNI isolates natural biological change without accounting for international or internal migration.

3

Analyze Total Dependency Ratio

Matched with non-working cohorts relative to economically productive population.

The dependency ratio divides youth (0–14) plus elderly (65+) by working-age adults (15–64).

4

Analyze Population Momentum

Matched with continued growth following fertility decline caused by youthful age structure.

A broad-based young age structure ensures high absolute birth numbers even when fertility rates drop.

Key Concept

Demographic Indices and Growth Dynamics

Question 18Question →

Pair each demographic concept listed on the left with the statement on the right that best describes its structural behavior or analytical measurement.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Demographic Momentum corresponds to the continued expansion of a population after reaching replacement-level fertility due to a broad young age base; Optimum Population corresponds to the demographic state where resources yield maximum income per head; Rate of Natural Increase corresponds to the net annual growth rate derived strictly from the difference between crude birth and death rates; and Fecundity corresponds to the physiological maximum capability to produce live offspring.

Demographic Momentum is the structural lag in growth caused by a youthful age distribution; Optimum Population is the balance point for maximum per capita output; Rate of Natural Increase measures birth minus death rates without migration; and Fecundity reflects physiological reproductive potential.

Step-by-Step Solution

1

Examine Demographic Momentum

Identified as population inertia driven by age structure.

Even when birth rates drop to replacement level, a large proportion of young individuals entering childbearing years ensures overall population growth persists.

2

Examine Optimum Population

Identified as economic equilibrium per capita.

It describes the exact demographic size relative to capital and technology that maximizes economic return per person.

3

Examine Rate of Natural Increase

Identified as vital rate growth metric.

Natural increase isolates internal growth derived by subtracting Crude Death Rate from Crude Birth Rate without incorporating net migration.

4

Examine Fecundity

Identified as biological reproductive capacity.

Fecundity represents potential biological output rather than empirical live birth rates (fertility).

Key Concept

Demographic Concepts and Population Growth Dynamics

Estimated Time:2m 0s

Question 19Question →

A demographic survey of an agricultural district in West Africa recorded a total population of $80{}000$ inhabitants. The survey broke down the population into $25{}000$ children (aged $0-14$ ), $45{}000$ economically active adults (aged $15-64$ ), and $10{}000$ elderly persons (aged $65$ and above). What is the overall age dependency ratio of this district?

77.8\%

128.6\%

43.8\%

55.6\%

Show answer & explanation

Answer: $77.8\%$

Answer

The overall age dependency ratio of the district is

77.8\%

.

The overall age dependency ratio is computed by taking the total dependent population (children aged 0–14 plus elderly aged 65+) and dividing it by the working-age population (aged 15–64), then multiplying by 100. Adding

25{}000

children and

10{}000

elderly gives

35{}000

dependents. Dividing

35{}000

by the

45{}000

productive adults yields approximately

77.8\%

.

Step-by-Step Solution

1

Calculate total dependent population

25{}000 + 10{}000 = 35{}000

The dependent population consists of children under 15 years and elderly citizens aged 65 and above.

2

Identify working-age population

45{}000

The economically active population includes individuals aged 15 to 64 years.

3

Apply age dependency ratio formula

\text{Age Dependency Ratio} = \frac{35{}000}{45{}000} \times 100 = 77.777...\% \approx 77.8\%

The age dependency ratio measures the demographic burden on the productive population per 100 working individuals.

Key Concept

Age Dependency Ratio Calculation

Estimated Time:1m 30s

Question 20Question →

In a community with a total population of $50,000$ , a local demographic survey recorded $1,250$ live births in one year. What is the Crude Birth Rate (CBR) per $1,000$ population for this community?

Show answer & explanation

Answer: 25

Answer

The Crude Birth Rate is 25 per 1,000 population.

The Crude Birth Rate is calculated by dividing total live births (

1,250

) by total population (

50,000

) and multiplying by

1,000

, resulting in

25

per

1,000

population.

Step-by-Step Solution

1

Identify the formula for calculating Crude Birth Rate (CBR).

\text{CBR} = \frac{\text{Total Live Births}}{\text{Total Population}} \times 1,000

.

Crude Birth Rate is defined as the number of live births per 1,000 people in a given population in a year.

2

Substitute the given values into the equation and solve.

\text{CBR} = \frac{1,250}{50,000} \times 1,000 = 25

.

Dividing

1,250

by

50,000

gives

0.025

, and multiplying by

1,000

yields

25

.

Key Concept

Crude Birth Rate Calculation

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