Inverse Proportions

11 soru

Soru 1Soru →

A naval destroyer traveling at an average speed of 24 knots24\text{ knots} completes a specific patrol route in 3 hours3\text{ hours} and 20 minutes20\text{ minutes}. If the captain is ordered to complete the identical route in 2 hours2\text{ hours} and 30 minutes30\text{ minutes}, what average speed must the destroyer maintain?

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Cevap: 32 knots32\text{ knots}

Cevap

The destroyer must maintain an average speed of 32 knots32\text{ knots}.
The distance of the patrol route is constant, meaning the product of the initial speed and time must equal the product of the new speed and time. Converting the travel times completely to minutes gives 200 minutes200\text{ minutes} and 150 minutes150\text{ minutes}. Using the inverse proportion formula, 24×200=480024 \times 200 = 4800. Dividing this constant by the required new time of 150 minutes150\text{ minutes} gives the necessary speed of 32 knots32\text{ knots}.

Adım Adım Çözüm

1
Convert both time durations entirely into minutes to ensure consistent units.
3 hours and 20 minutes=200 minutes3\text{ hours and } 20\text{ minutes} = 200\text{ minutes}, and 2 hours and 30 minutes=150 minutes2\text{ hours and } 30\text{ minutes} = 150\text{ minutes}.
Calculations involving mixed time units require a single common unit before a proportion can be accurately applied.
2
Identify the relationship between speed and time for a constant distance.
Speed and time are inversely proportional, governed by the equation S1×T1=S2×T2S_1 \times T_1 = S_2 \times T_2.
When the distance of a route remains the same, an increase in speed results in a proportional decrease in travel time.
3
Set up the inverse proportion equation and solve for the new speed (S2S_2).
24×200=S2×150  ⟹  4800=150×S2  ⟹  S2=3224 \times 200 = S_2 \times 150 \implies 4800 = 150 \times S_2 \implies S_2 = 32.
Isolating the unknown variable yields the required average speed to complete the route in the shorter timeframe.

Anahtar Kavram

Inverse Proportions in Speed and Time
Tahmini Süre:1m 30s
Soru 2Soru →

A unit of 3636 combat engineers can construct a perimeter defense system in 33 hours and 4545 minutes. If the commanding officer orders the defense system to be completed in exactly 11 hour and 4040 minutes, how many combat engineers in total must be assigned to the task, assuming all engineers work at the same constant rate?

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Cevap: 81

Cevap

81
The problem describes an inverse proportion because decreasing the allotted time requires increasing the number of workers to accomplish the identical task. By converting all times to minutes, the total required work effort is calculated as 3636 engineers ×\times 225225 minutes = 8,1008,100 engineer-minutes. Dividing this constant work effort by the new strict time constraint of 100100 minutes yields the total required personnel: 8181 engineers.

Adım Adım Çözüm

1
Convert both time durations entirely into minutes to establish a single, consistent unit of measure.
33 hours and 4545 minutes = (3×60)+45=225(3 \times 60) + 45 = 225 minutes. 11 hour and 4040 minutes = (1×60)+40=100(1 \times 60) + 40 = 100 minutes.
Converting to minutes prevents errors associated with mixed units and base-60 time fractions.
2
Set up an inverse proportion equation, recognizing that the total amount of work (personnel multiplied by time) remains constant.
Engineers1×Time1=Engineers2×Time2⇒36×225=x×100\text{Engineers}_1 \times \text{Time}_1 = \text{Engineers}_2 \times \text{Time}_2 \Rightarrow 36 \times 225 = x \times 100
When completing a fixed task, the number of workers and the time required are inversely proportional.
3
Solve the equation to find the total number of engineers required for the new timeframe.
8,100=100x⇒x=8,100100=818,100 = 100x \Rightarrow x = \frac{8,100}{100} = 81 engineers.
Dividing the total required engineer-minutes (8,1008,100) by the available minutes (100100) determines the necessary workforce.

Anahtar Kavram

Inverse Proportions
Tahmini Süre:1m 30s
Soru 3Soru →

A submarine leaves port with enough provisions to feed its standard crew of 120120 personnel for 6060 days. Before departure, 3030 additional mission specialists are assigned to the submarine. If the daily ration per person remains constant, how many days will the provisions last the newly expanded crew?

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Cevap: 48

Cevap

48
Because the total amount of food remains constant, an increase in personnel causes a proportional decrease in the number of days the food will last. The product of personnel and days is constant: 120×60=150×x120 \times 60 = 150 \times x. Solving for xx gives 7200/150=487200 / 150 = 48 days.

Adım Adım Çözüm

1
Calculate the total amount of provisions available.
120 personnel×60 days=7200 person-days120 \text{ personnel} \times 60 \text{ days} = 7200 \text{ person-days}
In an inverse proportion involving resources, the product of the number of consumers and the time the resource lasts represents the constant total resource.
2
Calculate the total number of personnel after the addition.
120+30=150 personnel120 + 30 = 150 \text{ personnel}
The problem states that 30 additional specialists were assigned, so the new crew size is the sum of the original and additional personnel.
3
Calculate the new duration the provisions will last.
7200 person-days÷150 personnel=48 days7200 \text{ person-days} \div 150 \text{ personnel} = 48 \text{ days}
Dividing the total constant resource by the new number of consumers yields the new time duration.

Anahtar Kavram

Inverse Proportions
Tahmini Süre:1m 0s
Soru 4Soru →

Match each inverse proportion scenario to its correct calculated value.

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Öğeler

Base rations feed 500500 troops for 30 days30\text{ days}. How long will the same rations last for 750750 troops?
A transport plane traveling at 400 mph400\text{ mph} completes a route in 6 hours6\text{ hours}. How long will the flight take at 600 mph600\text{ mph}?
A detail of 1212 sailors paints a deck in 8 hours8\text{ hours}. How long will it take 1616 sailors working at the same rate?
A 6060-tooth gear spins at 120 RPM120\text{ RPM}. What is the rotational speed of a connected 4545-tooth gear?

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Cevap

Each scenario represents an inverse proportion and must be matched with the value that maintains the constant product of the initial conditions.
Each match is mathematically determined by setting up an inverse proportion equation where the product of the initial states equals the product of the final states (x1⋅y1=x2⋅y2x_1 \cdot y_1 = x_2 \cdot y_2). Dividing the initial product by the new given value provides the correct corresponding answer.

Adım Adım Çözüm

1
Identify that each scenario represents an inverse relationship.
As one quantity increases (troops, speed, workers, gear teeth), the other quantity must decrease.
This determines that the product of the variables is constant (x1⋅y1=x2⋅y2x_1 \cdot y_1 = x_2 \cdot y_2), rather than the ratio.
2
Calculate the constant product (kk) for the initial conditions in each scenario.
The constants are 15,00015,000 troop-days, 2,400 miles2,400\text{ miles}, 96 man-hours96\text{ man-hours}, and 7,200 teeth-RPM7,200\text{ teeth-RPM}.
The constant represents the total amount of work, distance, resources, or mechanical transfer that must remain unchanged.
3
Divide the constant product by the new given variable to find the unknown required value.
The resulting values are 20 days20\text{ days}, 4 hours4\text{ hours}, 6 hours6\text{ hours}, and 160 RPM160\text{ RPM}.
Solving the equation x1⋅y1=x2⋅y2x_1 \cdot y_1 = x_2 \cdot y_2 for the unknown variable y2y_2 requires dividing the constant by x2x_2.

Anahtar Kavram

Inverse Proportions
Soru 5Soru →

A naval shipyard assigns 1515 automated painting drones to coat the hull of a cruiser in exactly 2 hours2\text{ hours}. If 55 of these drones are taken offline for maintenance before the job begins, how many minutes will it take the remaining drones to complete the coating?

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Cevap: 180180

Cevap

It will take 180 minutes for the remaining drones to complete the hull coating.
The correct answer is 180180. First, subtract the 55 offline drones from the initial 1515 to find that 1010 drones are actively working. Because the number of drones and the time required are inversely proportional, their product remains constant. The equation is 15×2=10×T215 \times 2 = 10 \times T_2, which solves to T2=3 hoursT_2 = 3\text{ hours}. Finally, converting 3 hours3\text{ hours} to minutes yields 3×60=180 minutes3 \times 60 = 180\text{ minutes}.

Adım Adım Çözüm

1
Determine the number of active drones.
15−5=10 drones15 - 5 = 10\text{ drones}
The 5 offline drones cannot work, so only the remaining drones will paint the hull.
2
Set up an inverse proportion equation.
15 drones×2 hours=10 drones×T215\text{ drones} \times 2\text{ hours} = 10\text{ drones} \times T_2
Work rate problems involve inverse proportions; as the number of workers decreases, the time required increases proportionally to keep the total work constant.
3
Solve for the new time (T2T_2) in hours.
30=10×T2⇒T2=3 hours30 = 10 \times T_2 \Rightarrow T_2 = 3\text{ hours}
Dividing the total required drone-hours (3030) by the number of active drones (1010) isolates the time.
4
Convert the required time into minutes.
3×60=180 minutes3 \times 60 = 180\text{ minutes}
The question explicitly asks for the final answer in minutes, not hours.

Anahtar Kavram

Inverse Proportions
Soru 6Soru →

A reconnaissance drone squadron currently takes 14 hours14\text{ hours} to completely map a designated tactical sector when using 66 identical drones simultaneously. If the task force commander requires the exact same sector to be mapped in 4 hours4\text{ hours}, how many total drones must be deployed?

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Cevap: 21

Cevap

2121 drones
The scenario describes an inverse proportion because increasing the number of active drones decreases the time required to finish the mapping. The total mapping workload is a constant 8484 drone-hours (6 drones×14 hours6\text{ drones} \times 14\text{ hours}). To complete this exact same workload in a compressed timeframe of 44 hours, a total of 2121 drones are needed (84÷484 \div 4).

Adım Adım Çözüm

1
Identify the relationship between the variables.
The number of drones and the time required are inversely proportional.
Completing a fixed amount of work faster requires proportionally more equipment.
2
Calculate the total amount of work required (the constant of variation).
6 drones×14 hours=84 drone-hours6\text{ drones} \times 14\text{ hours} = 84\text{ drone-hours}
In an inverse proportion (x×y=kx \times y = k), the product of the two variables remains constant.
3
Calculate the new number of drones required for the target time.
84 drone-hours÷4 hours=21 drones84\text{ drone-hours} \div 4\text{ hours} = 21\text{ drones}
Divide the total work constant by the new required time to solve for the missing variable.

Anahtar Kavram

Inverse proportions occur when one variable increases while another decreases such that their product remains constant (x1×y1=x2×y2x_1 \times y_1 = x_2 \times y_2).
Soru 7Soru →

A military transport vehicle's winch system uses a gear train consisting of three gears. The driving gear (Gear A) has 6060 teeth and rotates at 150 RPM150\text{ RPM}. It meshes with an idler gear (Gear B) which has 4545 teeth. Gear B meshes directly with the driven gear (Gear C). If Gear C must rotate at a speed of 5 revolutions per second5\text{ revolutions per second} to safely operate the winch, how many teeth must Gear C have?

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Cevap: 30

Cevap

30 teeth
The number of teeth on a gear and its rotational speed are inversely proportional. In a gear train, an idler gear (Gear B) only changes the direction of rotation, not the mathematical ratio between the first and last gears (TA×SA=TC×SCT_A \times S_A = T_C \times S_C). First, ensure the speed units match by converting Gear C's speed to RPM: 5 rev/s×60 seconds/minute=300 RPM5\text{ rev/s} \times 60\text{ seconds/minute} = 300\text{ RPM}. Then, equate the products for Gear A and Gear C: 60×150=TC×30060 \times 150 = T_C \times 300. Solving for TCT_C gives 9000÷300=309000 \div 300 = 30 teeth.

Adım Adım Çözüm

1
Identify the relationship in a gear train.
The product of teeth and rotational speed is constant across meshed gears (T1×S1=T2×S2T_1 \times S_1 = T_2 \times S_2). The idler gear (Gear B) does not change the final relationship between Gear A and Gear C.
To establish the mathematical formula needed and eliminate unnecessary variables.
2
Convert Gear C's speed to the same unit as Gear A (RPM).
5 revolutions/second×60 seconds/minute=300 RPM5\text{ revolutions/second} \times 60\text{ seconds/minute} = 300\text{ RPM}.
Both gears must use the exact same rate units before an accurate proportion can be calculated.
3
Set up the inverse proportion equation connecting Gear A to Gear C.
60 teeth×150 RPM=TC×300 RPM60\text{ teeth} \times 150\text{ RPM} = T_C \times 300\text{ RPM}.
To isolate the unknown variable based on the constant product rule of gears.
4
Solve the equation for the number of teeth on Gear C (TCT_C).
9000=300×TC9000 = 300 \times T_C, which simplifies to TC=9000÷300=30 teethT_C = 9000 \div 300 = 30\text{ teeth}.
To find the final required dimension for the driven gear.

Anahtar Kavram

Inverse Proportions in Compound Mechanics

Alternatif Yöntem

You can solve this in two steps by finding the idler gear's speed first. Gear B's speed: 60×150=45×SB→9000=45×SB→SB=200 RPM60 \times 150 = 45 \times S_B \rightarrow 9000 = 45 \times S_B \rightarrow S_B = 200\text{ RPM}. Then relate Gear B to Gear C (converted to 300 RPM300\text{ RPM}): 45×200=TC×300→9000=300×TC→TC=3045 \times 200 = T_C \times 300 \rightarrow 9000 = 300 \times T_C \rightarrow T_C = 30.
Tahmini Süre:1m 45s
Soru 8Soru →

A military logistics officer must calculate operational timelines based on available resources. Connect each situation below to its correctly calculated duration. Assume all rates are constant and inversely proportional.

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Öğeler

A runway repair takes 14 hours when 18 engineers are assigned. Time required if 21 engineers are tasked with the exact same repair.
A patrol boat traveling at 36 knots completes a coastal route in 4.5 hours. Time required to complete the route at a reduced speed of 27 knots.
Fifteen identical extractor fans ventilate a bunker complex in 6 hours. Time required if only 10 of these fans are operational.
A forward base's fuel cache can power 16 standard generators for 45 hours. Time the cache will last if 24 generators are running simultaneously.

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Cevap

The scenarios pair correctly with 12 hours, 6 hours, 9 hours, and 30 hours respectively based on their constant products.
Each scenario involves an inverse relationship where the product of the two given quantities forms a constant. Dividing this constant by the new condition yields the correctly paired time.

Adım Adım Çözüm

1
Identify the relationship for each scenario.
All four scenarios represent inverse proportions, meaning the product of the two variables (e.g., workers and time, speed and time) remains constant (x1×y1=x2×y2x_1 \times y_1 = x_2 \times y_2).
When one variable increases (like adding more workers or driving faster), the time required decreases proportionally.
2
Calculate the constant product for each individual scenario.
Engineer-hours: 18×14=25218 \times 14 = 252. Distance: 36×4.5=16236 \times 4.5 = 162. Fan-hours: 15×6=9015 \times 6 = 90. Generator-hours: 16×45=72016 \times 45 = 720.
This establishes the total amount of work, distance, or resource available before the change in variables.
3
Divide each constant product by the new given variable to find the new time.
Runway: 252÷21=12252 \div 21 = 12. Boat: 162÷27=6162 \div 27 = 6. Fans: 90÷10=990 \div 10 = 9. Generators: 720÷24=30720 \div 24 = 30.
Applying the inverse proportion formula (y2=kx2y_2 = \frac{k}{x_2}) isolates the unknown time.

Anahtar Kavram

Inverse Proportions in Work, Speed, and Resource Rates
Soru 9Soru →

A maintenance crew uses 44 identical pumps to empty a large aviation fuel tank in 1212 hours. If the crew decides to use 66 of these identical pumps instead, how many hours will it take to completely empty the tank?

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Cevap: 8

Cevap

8 hours
Because the number of pumps and time are inversely proportional, their product must remain constant. The initial scenario gives a product of 4 pumps × 12 hours = 48 pump-hours. To find the new time, divide the constant product of 48 by the new number of pumps (6). 48 ÷ 6 = 8 hours.

Adım Adım Çözüm

1
Identify the mathematical relationship between the variables.
The number of pumps and the time required are inversely proportional.
When working at a constant rate, increasing the number of machines decreases the time needed to complete the same job.
2
Set up the inverse proportion equation.
4×12=6×x4 \times 12 = 6 \times x
For inverse proportions, the product of the two variables remains constant (x1y1=x2y2x_1 y_1 = x_2 y_2).
3
Calculate the total pump-hours and solve for the new time.
x=48÷6=8x = 48 \div 6 = 8
Dividing the constant product (48) by the new number of pumps (6) isolates the unknown time variable.

Anahtar Kavram

Inverse Proportions
Tahmini Süre:45s
Soru 10Soru →

A detail of 1818 recruits can sweep and mop a large warehouse in 2020 minutes. If the schedule allows 1.51.5 hours for the task, how many recruits, working at the same constant rate, are required?

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Cevap: 44

Cevap

The correct answer is 44.
The scenario describes an inverse proportion because giving the detail more time to complete the task means fewer recruits are needed. By converting 1.51.5 hours to 9090 minutes and applying the inverse proportion relationship (18×20=x×9018 \times 20 = x \times 90), we find that exactly 44 recruits are required.

Adım Adım Çözüm

1
Calculate the total workload required to complete the task.
W1×T1=18×20=360W_1 \times T_1 = 18 \times 20 = 360 recruit-minutes.
In inverse proportion problems involving work, the product of the number of workers and their time represents a constant total amount of work.
2
Convert the new target time into the same unit (minutes).
1.5 hours=1.5×60=90 minutes1.5 \text{ hours} = 1.5 \times 60 = 90 \text{ minutes}.
Units must be consistent across the equation to yield a valid result.
3
Divide the total workload by the new target time to find the required number of recruits.
360÷90=4360 \div 90 = 4 recruits.
Applying the inverse proportion formula W2=Total Work÷T2W_2 = \text{Total Work} \div T_2 reveals how many workers are needed for the longer duration.

Anahtar Kavram

Inverse Proportions

Alternatif Yöntem

You can also solve this by finding the total work in 'recruit-hours'. First, convert 2020 minutes to 1/31/3 of an hour. The total work is 18 recruits×(1/3) hour=6 recruit-hours18 \text{ recruits} \times (1/3) \text{ hour} = 6 \text{ recruit-hours}. Since the new time is 1.51.5 hours, the required number of recruits is 6÷1.5=46 \div 1.5 = 4 recruits.
Tahmini Süre:1m 0s
Soru 11Soru →

Match each military work scenario with the correct time it would take to complete the task. Assume all personnel work at the same constant rate.

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Öğeler

2 mechanics take 6 hours to repair an engine. How many hours will it take 4 mechanics?
3 medics take 8 hours to inventory supplies. How many hours will it take 6 medics?
4 logisticians take 5 hours to load a transport. How many hours will it take 10 logisticians?
5 engineers take 6 hours to clear a path. How many hours will it take 6 engineers?

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Cevap

The 4 mechanics will take 3 hours, the 6 medics will take 4 hours, the 10 logisticians will take 2 hours, and the 6 engineers will take 5 hours.
Each scenario is an inverse proportion problem where the product of workers and time is a constant (total work). To find the new time, multiply the original workers by the original hours, then divide by the new number of workers.

Adım Adım Çözüm

1
Calculate the constant total work for each scenario.
Scenario 1: 12 hours. Scenario 2: 24 hours. Scenario 3: 20 hours. Scenario 4: 30 hours.
In inverse proportions, the product of workers and time is a constant (representing the total work required).
2
Divide the total work by the new number of workers.
12/4 = 3 hours; 24/6 = 4 hours; 20/10 = 2 hours; 30/6 = 5 hours.
Since the total work remains constant, dividing it by the available workforce yields the new time.

Anahtar Kavram

Inverse Proportions
Inverse Proportions Alıştırma Soruları — Armed Services Vocational Aptitude Battery (ASVAB) | Examkin