Question

If the sum of money triplets itself in 6 years at a certain rate of interest , find the time in which the amount Will become five times

Answer 1

let the Principal be Rs.100

amount=300

SI=p*r*t/100

200=100*r*5/100

200=5r

200/5=r

40=r

the rate of interest is 40%

required amount=500

required interest=400

400=100*40*t/100

400=40t

400/40=t

10=t

it will take 10 years to be 5 times.

Answer 2

Let the amount be 100.

100 + 100 ×5 x 5R/100 =300.

100 + 5R = 300

R = 40.

100 + 100 × N x 40/100= 500

40N = 400

N = 10.