Correct Answer - Option 1 : 3 : 11
Given:
The ratio of copper to tin of 1st alloy = 3 : 4
The ratio of copper to tin of 2nd alloy = 1 : 6
Weight of 1st alloy = 7 kg
Weight of 2nd alloy = 21 kg
Calculation:
The quantity of copper in 7 kg alloy = (3/7) × 7 = 3 kg
The quantity of tin in 7 kg alloy = (4/7) × 7 = 4 kg
The quantity of copper in 21 kg alloy = (1/7) × 21 = 3 kg
The quantity of tin in 21 kg alloy = (6/7) × 21 = 18 kg
New alloy = 1st alloy + 2nd alloy
Total quantity of copper in new alloy = 3 + 3 = 6 kg
Total quantity of tin in new alloy = 4 + 18 = 22 kg
The ratio of copper to tin in new alloy = 6 : 22 = 3 : 11
∴ The ratio of copper to tin in the new alloy is 3 : 11.