Question

At a certain rate of simple interest, Rs. 700 in 2 years amounts to Rs. 840. If the rate of interest is increased by 2%, what will be the amount after 3 years?​

Answer 1

Answer:

let the rate be r%P.a.

principal=P=Rs 700

Amount=A=Rs 840

Time=t=2years

Simple Interest=I=A-p=840-700=Rs 140

therefore

I=(Pxrxt)/100

140=(700xrx2)/100

140=14xr

r=10%P.a.

After three years

Time=t=3years

principal=P=Rs700

Rate=r=10+(2%of10)=10+(2/100x10)=10+0.2=10.2%

I=pxrxt/100

I=700x10.2x3/100

I=Rs. 214.2

therefore

Amount=P+I=700+214.2=Rs 914.2

Hope it helps