If a certain sum of money becomes thrice of itself in 8 years 6 months at simple interest, then what will be the annual rate of interest?

Correct option is D

Given: A certain sum of money becomes thrice itself in 8 years 6 months at simple interest.
Formula Used: Simple Interest = (Principal × Rate × Time) / 100
Solution:
Let the principal amount be P.
Final amount = 3P, so the interest = 3P - P = 2P.
2P = (P × R × 8.5) / 100.
R = 23.52 %