By using the formula, find the amount and compound interest on:
A sum of money amounts to Rs 10240 in 2 years at 6 2/3% per annum, compounded annually. Find the sum.
Amount (A) = Rs. 10240
Rate (r)=6+2/3%=20/3% p.a.Period
(n) = 2 years
Let sum = P, then A=P(1+r/100)n
⇒ 10240=P(1+20/(3×100))2⇒ 10240=P(1+1/15)2⇒ 10240=P×(16/15)2∴ P=Rs. 10240×(15/16)2=Rs. 10240×15/16×15/16=Rs. 9000
∴ Sum=Rs. 9000 Ans.