Question

A sum amount to Rs.9680 in 2 year and to Rs.10648 in 3 year compounded annually. Then, the sum and rate of interest respectively are:

(a) Rs.8000, 10%
(b) Rs.8500, 10%
(c) Rs.8500, 9%
(d) Rs.8000, 9%

Wrong answer will be reported......please give correct answer........​​

Answer 1

Step-by-step explanation:

Amount = P[ (1+r)^n ]

9680 = P [ (1+r)^2 ] -(eq 1)

10648 = P [ (1+r)^3 ] -(eq 2)

On dividing eq 1 by eq 2 , we get

1210/1331 = 1/(1+r)

1210+1210r = 1331

r = 121/1210

r = 1/10. (means rate = 10%)

Putting value of r in any of the eqns ,we get

P = 8000

For , 1 2/5 yrs or 7/5 yrs -

A = 8000 [ (1+1/10) ^ (7/5) ]

A = 8000 [ (1.1) ^ (1.4) ]

A = 8000*1.14274

A = 9141.9

So , A = Rs. 9142 (approx.)

I didn't got the exact ans but its closest to option b).

Answer 2

hope it helps you ❤️...