Question

If simple interest for a sum of rs. 3,100 for 4 years is rs. 40 more than the simple interest of rs. 2900 for the same duration at the same rate of interest then the rate of interest is

Answer 1

5%

Let rate of interest be r%.

1st case:

sum=Rs.3100,t=4 years

SI=prt/100

=3100×4×r/100

=Rs.124r

2nd case:

sum=Rs.2900,t=4 years

SI=prt/100

=2900×4×r/100

=Rs.116r

difference=124r-116r=8r

8r=40

r=5