Question

the CI on a sum of money for 2 years is 102.50 and SI for the same sum ,same period and the same rate is 100.find sum and rate

Answer 1

It is $1,000.00 at 5% interest.

Simple Interest
1,000 @ 5% Interest = $50 per year so
2 years yields $100.00

Compound Interest
$1,000 @ 5% Interest for 2 years =
1,000 * (1+.05)^2
1,000 * 1.1025
= $1,102.50
The interest of which equals $102.50