If in 13 years a fixed sum doubles at simple interest, what will be the interest rate per year? (Correct to two decimal places)
Answer & explanation
Correct answer: option 2
Given :-
In 13 years fixed sum doubles itself at simple interest.
Amount = Principal + Interest
Let fixed sum = P and final amount after 13 years = 2P
SI = 2P - P = P
Simple Interest = \(\frac{Principal ×Rate × Time }{100}\)
P = \(\frac{P ×Rate × 13 }{100}\)
Rate = \(\frac{P × 100 }{P×13}\)
= 7.69%