Correct Answer - Option 3 : 4 : 5
Given:
Ratio of the rates of Simple Interests in two banks A and B = 5 : 4
Half-yearly interests from both the banks are equal.
Formula Used:
Simple Interest (SI) = (P × R × T)/100;
where P = principal, R = Rate of Interest, T = Time period.
Calculation:
Let the principal amounts invested in banks A and B be A and B, respectively.
Let the respective rates of simple interest for banks A and B be 5x and 4x
Using the formula for SI, we get:
SI for bank A = (A × 5x × 0.5)/100
Also, SI for bank B = (B × 4x × 0.5)/100
Since the SI is the same for both the banks, we get:
(A × 5x × 0.5)/100 = (B × 4x × 0.5)/100
⇒ 2.5A = 2B
⇒ A/B = 4/5
∴ The ratio in which deposit should be made in the banks A and B should be 4 : 5