Q. Mohan obtained a loan of Rs 2000 against some security. If rate of interest is 5â??per annum compound annually, find interest and amount paid by him at the end of two years.
Ans: principal amount= 2000
Short cut
First find square of(1+ 5/100)= 1.1025
Amount is paid 1.1025×2000= 2205rs
Interest is 2205-2000=205rs
If it is ask only interest we don't need to calculate amount we find it by
Interest is paid (1.1025-1)×2000=205rs