IBPS SO Prelims Exam Model Paper 1

Given:
The ratio of gold and copper in alloys A and B are 6 : 1 and 4 : 1
A and B are taken in the ratio 4 : 5 and melted to form a new alloy C
Calculation:
Since, the ratio of alloys A and B is 4 : 5
So, Let the amount of alloys A and B are 28 kg and 35 kg
So, the amount of gold in alloy A = 28 ×

6

7

= 24 kg
And the amount of copper in alloy A = 28 ×

1

7

= 4 kg
And the amount of gold in alloy B = 35 ×

4

5

= 28 kg
And the amount of copper in alloy B = 35 ×

1

5

= 7 kg
So, the amount of gold in C = 24 + 28 = 52 kg
And the amount of copper in C = 4 + 7 = 11 kg
∴ The required ratio = 11 : 52