Correct Answer - Option 4 : 200 gram
Given:
Ratio of Gold and silver = 7 ∶ 3
Quantity of the alloy = 1000 gram
Calculation:
Let quantity of Gold added to be x grams
Quantity of Gold = (7/10) × 1000
⇒ 7 × 100
⇒ 700 grams
Quantity of silver = (3/10) × 1000
⇒ 3 × 100
⇒ 300 grams
Now,
According to the question,
(700 + x)/300 = 3/1
⇒ (700 + x) × 1 = 300 × 3
⇒ 700 + x = 900
⇒ x = 900 – 700
⇒ x = 200
∴ The Quantity of Gold added will be 200 grams