Question

The ratio of gold to silver in alloys A and B are 2 : 3 and 7 : 3 respectively. If both are melted together and made into a new alloy C, then find the ratio of gold and silver in the new alloy C.

1. 15 : 7
2. 11 : 9
3. 13 : 7
4. 13 : 9

Answer 1

Correct Answer - Option 2 : 11 : 9

Given:

In alloy A, the ratio of gold to silver is = 2 : 3

In alloy B, the ratio of gold to silver is = 7 : 3

Calculation:

Let the mixture is taken be 1 kg

In alloy A,

Gold = (2/5) × 1

⇒ Gold = (2/5)

Silver = (3/5) × 1

⇒ Silver = (3/5)

In alloy B,

Gold = (7/10) × 1

⇒ Gold = (7/10)

Silver = (3/10)× 1

⇒ Silver = (3/10)

The ratio of gold to silver in new alloy C = {(2/5) + (7/10)} : {(3/5) + (3/10)} 

⇒ (11/10) : (9/10)

⇒ 11 : 9

∴ The Ratio of Gold to silver in alloy C is 11 : 9.