# An alloy contains the copper and aluminum in the ratio of 7 : 4 While making the weapons from this alloy, 12% of the alloy got destroyed. If there is 12 kg of aluminum in the weapon, then weight of the alloy required is :

A. 14.4 kg

B. 37.5 kg

C. 40 kg

D. 48 kg

**Answer: Option B **

__Solution(By Examveda Team)__

Copper : Aluminum = 7 : 4Let Copper and Aluminum in the weapon be 7x and 4x respectively

Given,

Aluminum in weapon = 12 kg

So,

→ 4x = 12

→ x = 3

Copper = 7x = 7 × 3 = 21 Kg.

Total alloy in the weapon = 12 + 21 = 33 kg

But 12% alloy get destroyed in making the weapon, i.e. 88% alloy is used in the weapon, so,

→ 88 % alloy = 33 kg

→ 100 % alloy = 37.5 kg

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## Comments ( 4 )

Related Questions on Percentage

A. $$\frac{1}{4}$$

B. $$\frac{1}{3}$$

C. $$\frac{1}{2}$$

D. $$\frac{2}{3}$$

88% = 33kg

So,

1% = 33/88 kg

Thus,

100% = (33 *100)/88 = 37.5 Kg.

Since 88% of alloy weight as 33kg,

therefore 100% weight of allow is (100 *33 )/88 = 37.5kg

how 100%=37.5?

How is 100% alloy =37. 5