Question

An amount becomes Rs.6,000 to Rs.7200 in 4 years. What will be the amount in 5 years if the rate of interest is increased by 2% per annum at simple interest?
1. Rs. 8100
2. Rs. 6000
3. Rs. 7200
4. Rs. 8000

Answer 1

Correct Answer - Option 1 : Rs. 8100

Given:

Amount = Rs. 7200

Principal = Rs. 6,000

Time = 4 years

Formula Used:

Amount = Principal + Interest

Simple interest = (Principal × Time × Rate of interest)/100

Calculation:

Simple interest = Amount - Principal

⇒ Simple interest = Rs. 7200 - Rs. 6000

⇒ Simple interest = Rs. 1200

Simple interest = (Principal × Time × Rate of interest)/100

⇒ 1200 = (6000 × 4 × Rate of interset)/100

Rate of interest = 5% p.a.

Now, 

Increase rate of interest =  5%p.a. + 2% p.a. = 7% p.a

Time = 5 years

⇒ Simple interest = (6000 × 5 × 7)/100

⇒ Simple interest =  2100 

Amount =  Principal + Simple interest

⇒ Amount = Rs. 6000 + Rs. 2100 = Rs. 8100

∴ The amount in 5 years will be Rs. 8100.