Correct Answer - Option 1 : 8%
Formula used
SI = (P × R × T)/100
SI = Simple interest
P = Principal
R = Rate
T = Time
Calculation
Let principal be 100Rs
⇒After 25 years principal = 300
⇒ SI = 300 - 100 = Rs.200
⇒ 200 = (100 × r × 25)/100
⇒ r = 8 %
∴ At 8 percent per annum simple interest, a sum of money triple itself in 25 yr