In certain years a sum of money is doubled to itself at the rate 25% simple interest per annum, then find the time.

16 years 12 years 8 years 4 years

4 years

ATQ P  :   A    :    S.I.                   1  :   2    :     1  ⇒ S.I. = \(\frac{PRT}{100}\) ⇒  1 = \(\frac{1 × 25 × T}{100}\) ⇒  T = 4 years