Question

A certain sum of simple Interest amount of 3900 in 3 years and 4500 in 5 years find sum and rate of interest per annum

Answer 1

3----3900
5----4500
________
so (S.I)2 year =600
interest of 1 year be 300
---------------3-----------900

so sum=3900-900=3000
rate= 300×100÷3000=10%