Task: Question Answering
Input (English): Problem: peter invested a certain sum of money in a simple interest bond whose value grew to $ 300 at the end of 3 years and to $ 400 at the end of another 5 years. what was the rate of interest in which he invested his sum ?
Options: a. 12 %, b. 12.5 %, c. 6.67 %, d. 6.25 %, e. 8.33 %
Output (English): e