A person borrowed some money on simple interest. After 3 years, he returned 4/3 of the money to the lender. What was the rate of interest?

Correct option is D

Given:
Principal amount (P) = Let the borrowed amount be P
Time (T) = 3 years
Amount returned =$$\frac{4}{3} P$$​​
Simple Interest (SI) = Amount returned - Principal = $$\frac{4}{3} P - P = \frac{P}{3}$$​​
Formula Used:
Simple Interest (SI) = $$\frac{P \times R \times T}{100}$$​​
Solution:
​$$\frac{P}{3} = \frac{P \times R \times 3}{100}\\\ \\\frac{1}{3} = \frac{R \times 3}{100}\\\ \\R = \frac{100}{9} = 11.11\%\\\ \\$$​​
Thus, the rate of interest is 11.11% = 11$$\frac19$$​​%