IBPS Clerk Prelims Model Paper 21

Let P = Rs.x, T = 2 years, R = 10% p.a, and C.I. = Rs. 420.
Then, A=P(1+

R

100

)n
A = x(1+

0

100

)2
A = x(

11

10

)2
A =

121x

100

Because C.I. = A – P
420 =

121x

100

−x
x = 2000
Now, S.I. =

P×R×T

100

=2000×10×

2

100

= Rs. 400
Therefore, the required interest is Rs. 400.