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Zorluk: ZorCalculating Percentages of Quantities

A military supply depot transfers 40%40\% of its medical kit inventory to a forward operating base. The following week, the depot transfers 30%30\% of its remaining medical kits to a local training facility. If the depot currently has 1,2601,260 medical kits left in stock, what was the original number of medical kits in the inventory?

  1. 3,0003,000Cevap
  2. B
    4,2004,200
  3. C
    7,0007,000
  4. D
    2,1422,142

Cevap

The original number of medical kits in the inventory was 3,0003,000.
The correct approach requires tracking the percentages relative to the original inventory. After 40%40\% of the kits are transferred, 60%60\% remains. The second transfer removes 30%30\% of this 60%60\%, meaning 70%70\% of the 60%60\% stays in stock. Multiplying 0.60×0.700.60 \times 0.70 gives 0.420.42, which means the final 1,2601,260 kits represent exactly 42%42\% of the original inventory. Dividing 1,2601,260 by 0.420.42 yields the original starting total of 3,0003,000.

Adım Adım Çözüm

1
Determine the percentage of inventory remaining after the first transfer.
100%−40%=60%100\% - 40\% = 60\% of the original inventory remains.
The second transfer is based on this remaining amount, not the original total.
2
Calculate the percentage of the original inventory that remains after the second transfer.
The second transfer takes 30%30\% of the remaining kits, meaning 70%70\% of those kits stay at the depot. 0.70×0.60=0.420.70 \times 0.60 = 0.42, so 42%42\% of the original inventory is left.
To set up an equation, the final quantity must be related to a single percentage representing a portion of the original whole.
3
Solve for the original number of medical kits.
Let xx be the original inventory. 0.42x=1,2600.42x = 1,260. Dividing both sides by 0.420.42 gives x=1,260÷0.42=3,000x = 1,260 \div 0.42 = 3,000.
Dividing the final remaining quantity by its corresponding decimal percentage yields the original starting value.

Anahtar Kavram

Calculating successive percentages and working backward from a final quantity to find an original whole.
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