Correct Answer - Option 1 : 4250
Given:
In 1 Kg alloy, the ratio of Zinc and Copper = 3 ∶ 7.
Calculation:
Let the quantity of zinc to be added be x.
The quantity of zinc in 1 kg alloy = (3/10) × 1000 = 300 grams
The quantity of copper in 1 kg alloy = 1000 - 300 = 700 grams
According to question,
(300 + x)/700 = 13/2
⇒ 600 + 2x = 9100
⇒ 2x = 9100 - 600
⇒ x = 8500/2 = 4250.
∴ The quantity of zinc to be added is 4250 grams.