A sum of rs400 amounts to rs480 in 4years. What will it amount to if the rate of interest is increased by 2% p.a

Answer 1

let the current rate be i where i is a decimal
e.g. 5% = .05 = i

at the current rate:
400(1+i)^4 = 480
(1+i)^4 = 1.2
take 4th root of both sides
1+i = 1.046635..
i = .046635..

at new rate i = .066635....
amount = 400(1.066635...)^4
= ....

Answer 2

Madharchod SIMple interest h