Question

Q11. The simple interest in 3 years and compound interest in 2 years on a given sum of money a
certain rate are *1800 and 1272. calculate (i) the rate of interest (ii) the principal​

Answer 1

Answer:

Compound interest for 2 years=Rs.832

Simple interest for 3 years=Rs.1200

As simple interest for each year remains the same.

So, simple interest for 2 years=1200×

3

2

=Rs.800

We know that,

CI

2 year

−SI

2 year

=

200

SI

2 year

×R

=

(100)

2

PR

2

832−800=

200

800×R

32=4×R

R=8%

Again, CI

2 year

−SI

2 year

=

(100)

2

PR

2

32=

100

2

P×(8)

2

32=

10000

P×64

P=

64

32

×10000=5000

Hence, the principal is Rs.5000.