Kamala borrowed from Ratan a certain sum at a certain rate for two years simple interest. She lent this sum at the same rate to Harti for two years compound interest. At the end of two years she received Rs. 210 as compound interest, but paid Rs. 200 only as simple interest. Find the sum and the rate of interest.

Kamala borrowed from Ratan a certain sum at a certain rate for two years simple interest. She lent this sum at the same rate to Harti for two years compound interest. At the end of two years she received Rs. 210 as compound interest, but paid Rs. 200 only as simple interest. Find the sum and the rate of interest.

Given,

C.I that Kamla receive = Rs.210

S.I that Kamla paid = Rs.200

Time = 2 years

So,

S.I =

=

C.I =

= 210 =

=

= 210 =

= R = 10%

From equation (i)

=

=

14