Question

a certain sum of money yields q SI of Rs.4000 at the rate of 10%pa after 2 years.at what rate %p.a will the same sum of money yields a compound interest of Rs.6620 in 3 years compounded yearly?​

Answer 1

Answer:

Principal =4000

Compound interest for two years =Rs410

∴ Amount at the end of 2 years =A=Rs(4000+410)

=Rs.4410

⇒ Time 2 years

Let the rate of interest be r% p.a.

we have,

⇒A=P(1+

100

r

)

2

⇒4410=4000(1+

100

r

)

2

⇒

400

441

=(1+

100

r

)

2

⇒

20×20

21×21

=(1+

100

r

)

2

⇒

20×20

21×21

=

100

r

+1

⇒

20

21

−1=

100

r

⇒

20

1

×100=r

∴r=5%p.a.

Hence, the answer is 5%

Answer 2

Answer:

Step-by-step explanation:

Principal=x     Rate=10%       Time=2 Years

SI=PRT/100

=x*10*2/100

=x=20000

P=20000

A=26200

A=$P(1+R/100)\x^{n}$

=$20000(1+R/100)^{3}$=26200

R=33.1%