Question

12. A certain sum of money amounts to 1,008/- in 2 years and the same sum of money amounts to 1,164/- in 3 years and 6 months. Find the sum and the rate of interest.?​

Answer 1

Answer:

let that sum be 'x' and rate be 'r'

Step-by-step explanation:

A1 = sum +s.i1

1008 = x + x×r×2/100

1008 =x( 1 + 2r/100)

100800 = x(100+2r) --(1)

t2 = 3yrs6m = 3 yr+ 6/12 yr= 7/2yr

A2 = sum + s.i2

1164 = x + x×r×7/200

232800 =x(200+7r) --(2)

devide (2) by (1)

232800/100800 = 100+7r/100+2r

2328/1008 = 200+7r/100+2r

31200 = 2400r => r = 13%

from(1) 100800 = x[100+2(13)]

x = 100800/126 = Rs 800

Answers: sum = Rs800, rate = 13%