Question

Difficulty: HardFraction Multiplication and Division in Context

Read the scenario and determine the final quantity. Fill in the blank with the correct numeric value.

Answer:A military engineering unit has a stockpile of 315315 tons of crushed rock. They use 49\frac{4}{9} of the total stockpile to reinforce a main supply route. The unit commander then orders the remaining crushed rock to be divided into equal truckloads of 121212 \frac{1}{2} tons each for distribution to forward operating bases. The unit will be able to distribute exactly 【14】 full truckloads to the forward bases.

Answer

14
By first finding the remaining amount of crushed rock (175175 tons) and then dividing it by the size of each load (121212 \frac{1}{2} tons), we determine there are exactly 1414 truckloads.

Step-by-Step Solution

1
Determine the fraction of the stockpile that remains after the main supply route is reinforced.
1−49=591 - \frac{4}{9} = \frac{5}{9}
The truckloads are created from the remaining crushed rock, not the amount used for the main supply route.
2
Calculate the total weight of the remaining crushed rock.
315×59=315×59=35×5=175315 \times \frac{5}{9} = \frac{315 \times 5}{9} = 35 \times 5 = 175 tons
This gives the exact quantity of rock available to be divided into individual truckloads.
3
Determine the number of truckloads by dividing the remaining weight by the weight per truckload.
175÷1212=175÷252=175×225=7×2=14175 \div 12 \frac{1}{2} = 175 \div \frac{25}{2} = 175 \times \frac{2}{25} = 7 \times 2 = 14 truckloads
Dividing the total available weight by the capacity of each load yields the total number of loads.

Key Concept

Solving multi-step word problems involving multiplication of whole numbers by fractions and division by mixed numbers.
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