A sum of money amounts to Rs.10648 in 3 years and Rs.9680 in 2 years. The rate of interest is :
5%
10%
15%
20%
Explanation:
Let P be the principal and R% annum be the rate.
Then P (1+R100)3=10648(1+R100)3=10648...(i)
and P (1+R100)2=9680(1+R100)2=9680 ....(ii)
On dividing (i) by (ii), we have
(1+R100)=106489680(1+R100)=106489680
or R100=9689680=110R100=9689680=110
or R = 110×100=10%110×100=10%
Let P be the principal and R% annum be the rate.
Then P (1+R100)3=10648(1+R100)3=10648...(i)
and P (1+R100)2=9680(1+R100)2=9680 ....(ii)
On dividing (i) by (ii), we have
(1+R100)=106489680(1+R100)=106489680
or R100=9689680=110R100=9689680=110
or R = 110×100=10%110×100=10%