Correct Answer - Option 4 : 4%
Given:
The Sum of money doubles itself in 25 years.
Concept:
Simple interest is the interest calculated on the principal portion of the loan or the original contribution to the saving account.
Formula Used:
Simple Interest = (P × R × T)/100
S.I = Amount - Sum
Calculation:
Let the sum be 'P' then Amount after 25 years = 2P
S.I = 2P - P = P
P = (P × R × 25)/100
⇒ R = 100/25 = 4%
∴ The rate of interest per annum is 4%.