Question

Zinc and copper are in the ratio of 5 : 3 in 200 gm of alloy. How much grams of copper be added to make the ratio as 3 : 5 ?

• A. 400/3
• B. 1/200
• C. 72
• D. 66

Answer 1

Answer: (A)

400/3

Zinc earlier = (5 *200)/8 = 125 gm
Copper earlier = (3 *200)/8 = 75 gm
Now, Zinc is same but copper is to be added to make the ratio 3 : 5
Quantity of copper added later = (125 *5)/3 = 625/3
So extra copper added = (625/3) - (75) = (625 - 225)/3 = 400/3.