Correct Answer - Option 2 : 25%

**Given:**

Time = 16 years

A certain sum of money becomes 5 times of itself.

**Concept used:**

R = (S.I. × 100)/(P × T)

S.I. = A – P

Where,

R → Rate

S.I. → Simple interest

P → Principal

T → Time

**Calculations:**

Let Principal x and amount 5x

S.I. = A – P

⇒ 5x – x = 4x

R = (S.I. × 100)/(P × T)

R% = (4x × 100)/(x × 16) = 25%

**∴ The rate of interest is 25%**