Question

A certain sum amounts to 7200 in 3years an 8400 in 4 years. Find the sum and rate of interest

Answer 1

Answer:

If Simple interest:

Let principal be P.

ATQ, Amount after 3 years =7200

Amount after 4 years = 8400

Interest for 1 year = 8400 - 7200 = 1200

Principal = 7200 - (1200*3) = 3600

Rate = SI * 100/ T*P

= 1200*100/3600*1

= 120000/3600

= 33.33%