Question

A sum of money triples itself, the rate of simple interest being 5% per annum. What is the time period ? 
1. 40 Years
2. 30 Years
3. 20 Years
4. 60 Years

Answer 1

Correct Answer - Option 1 : 40 Years

Given: 

Sum of Money becomes 3 times

Rate of simple interest = 5% per annum

Formula Used;

Simple interest = (Principal × rate × time)/100

Amount =  Principal + Simple interest

Calculation:

Let the principal be Rs A

Then after tripling Amount will become 3A

Simple interest = 3A - A = 2A

2A = (A × 5 × time)/100

⇒ Time = (2A × 100)/(A × 5) = 40 years

∴ The Time period is 40 years.