In what time will the simple interest on ₹2200 at 6% per annum be the same as that on ₹1650 at 9% per annum in 10 years?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 11 years and 3 months
Simple interest is \(\frac{P\times R\times T}{100}\). Work out the interest on ₹1650 for 10 years first, then find the time in which ₹2200 at 6% earns the same amount.
Interest on ₹1650 at 9% for 10 years \(\displaystyle =\frac{1650\times9\times10}{100}=1485\)
Interest on ₹2200 at 6% for \(T\) years \(\displaystyle =\frac{2200\times6\times T}{100}=132T\)
\(132T=1485\), so \(\displaystyle T=\frac{1485}{132}=11.25\) years
0.25 year \(=\) 3 months, so \(T=\) 11 years and 3 months