The compound interest accrued on a sum of Rs. 4400 at the end of 2 years is Rs. 1,119.36. What would be the simple interest on the sum at the same rate for double the time?
1. Rs. 2,211
2. Rs. 2,121
3. Rs. 2,122
4. Rs. 2,112
1. Rs. 2,211
2. Rs. 2,121
3. Rs. 2,122
4. Rs. 2,112
Correct Answer – Option 4 : Rs. 2,112
Given:
Principal Amount (P) = Rs. 4400
Time Period (T) = 2 years
Compound Interest after two years (CI) = 1119.36
Formulae Used:
If Principal = P, Time period = T, and Rate of Interest = R;
Compound Interest (CI) = {P [1 + (R/100)]T} – P; and
Simple Interest (SI) = (P × R × T)/100
Calculation:
Using the formula for CI, we can obtain the rate of interest (R) as:
Compound Interest (CI) = {P [1 + (R/100)]T} – P
⇒ 1119.36 = {4400 × [1 + (R/100)]2} – 4400
⇒ 5519.36/4400 = [(100 + R)/100]2
⇒ (100 + R)2 = 1.2544 × 10000
⇒ (100 + R) = 112
⇒ R = 12%
Now, for calculating the Simple Interest,
Rate of Interest remains the same, so Rate = R
Time period doubles, so T = 4 years
Hence, we can calculate the value of Simple Interest (SI), as:
SI = (4400 × 12 × 4)/100
⇒ SI = Rs. 2112
∴ The simple interest on the sum at the same rate for double the time is Rs. 2112