Question

some of money lent at simple interest amount to rs 2880 in 2 years and rs 3600 in 5 years find the sum and the rate of interest​

Answer 1

Step-by-step explanation:

Let the sum is rs x and the rate of interest is r%.

1st time simple Interest =(x*2*r/100

From question, x+(x*2*r)/100 =2880

2x(100+r) =288000

x = 288000/(100+2r) . . . . . . . (1)

2nd time simple interest =(x*5*r)/100

From question, x+(x*5*r)/100 = 3600

5x(100+r) =360000

x = 360000/(100+5r) . . . . . . . .(2)

Then, 288000/(100+2r) = 360000/(100+5r)

288/(100+2r)= 360/(100+5r)

28800+1440r = 36000+720r

720r = 7200

r = 10%

Putting r= 10 in eq (1),

x= 288000/(100+2*10)

x = 288000/120 =Rs 2400