Question

1. Difference between the compound interest and the simple interest on a certain sum for 2 years 5%
per annum.
Find the sum
​

Answer 1

Answer:

Given : n=2 years, R=7

2

1

​

=

2

15

​

S.I.−C.I.=360 ....... (i)

S.I. =

100

P×n×R

​

=

100

P×2×

2

15

​

​

=

100

15P

​

Amount (A)=P(1+

100

R

​

)

n

=P(1+

2×100

15

​

)

2

=P(1+

40

3

​

)

2

C.I. =A−P

=P(1+

40

3

​

)

2

−P

=P(1+

1600

9

​

+

40

2×3

​

−1)

=P(

1600

9

​

+

40

6

​

)

C.I.=P(

1600

249

​

) ........ (ii)

It is given that,

∣S.I.−C.I.∣=360

⟹

∣

∣

∣

∣

∣

​

100

15P

​

−P(

1600

249

​

)

∣

∣

∣

∣

∣

​

=360

⟹

1600

9P

​

=360

⟹P=64000

Hence, the sum is Rs. 64,000.

Verification :-

S.I. =

100

P×n×R

​

=

2×100

64000×2×15

​

=9600

C.I. =P[(1+

100

R

​

)

n

−1]

=64000[(1+

2×100

15

​

)

2

−1]

=9960

∣S.I.−C.I.∣=∣9600−9960∣=360.

Hope it will help you mate ......................

Step-by-step explanation: