Question

Question:
At what rate per cent per annum will Rs.4000 amount to Rs.4410 in 2 years when compounded annually?​

Answer 1

Answer:

Principal P = Rs.4000

Time(t) = 2 years

Amount A = Rs. 4410

Rate of interest =?

Formula of Amount of compound interest

$a \: = \: p(1 + \frac{ {r}}{100} )^{t}$

Let rate%=r

So 4410 = 4000(1 + r/100)^2

=> (1 + r/100)^2 = 4410/4000 = (21/20)^2

=> (1 + r/100) = 21/20

=> r/100 = 1/20

=> r = 100/20 = 5

So at 5% per annum Rs 4000 will amount to RS 4410 in 2 years when compounded annually

hope it helps!

Answer 2

Answer:

4410=4000(R/100+1)2

4410/4000=R/100+1)2

441/400=R/100+1)2

21/20=R/100+1

21/20-1=1/20

1/20=R/100

20R=100

R=5%