The simple interest for 9 years on a principal is $\frac{3}{5}$ of the principal. What is the rate of interest per annum?
Answer & explanation
Correct answer: option 3
Simple Interest = \(\frac{3 }{5 }\) × Principal
Simple Interest = \(\frac{Principal ×Rate × Time }{100}\)
\(\frac{3 }{5 }\) × Principal = \(\frac{Principal ×Rate × 9 }{100}\)
\(\frac{3 }{5 }\) = \(\frac{Rate × 9 }{100}\)
Rate = \(\frac{20 }{3}\)%
= 6\(\frac{2 }{3}\)%