Question

A sum of money doubles itself in 4 years at simple interest, then find the rate of interest.
1. 20%
2. 25%
3. 12%
4. 18%

Answer 1

Correct Answer - Option 2 : 25%

Given:

A sum of money doubles itself in 4 years 

Concept used:

S.I. = A – P

R = (S.I. × 100)/(P × T)

Where,

S.I. → Simple interest 

A → Amount

P → Principal 

R → Rate 

T → Time 

Calculations:

Let the principal be x 

So, Amount = 2x 

S.I. = 2x – x = x 

R = (S.I. × 100)/(P × T)

⇒ (x × 100)/(x × 4)

⇒ 25% 

∴ The rate of interest is 25%