Question

in how many years rupees 1000 amount to rupees 1400 at rate of 4% p. a

Answer 1

a=p(1+rt/100)

1400=1000(1+4t/100)

1400/1000=1+t/25

7/5-1=t/25

2/5=t/25

t=10 years

Answer 2

In 10yrs
As Principal =1000
Amount =1400
Therefore Simple Interest =1400-1000=400
S.I=P*R*T divided by 100
Let the time be x yrs.
Then, 400=1000 *4*x divided by 100
400=40x
Then x=10 yrs