Question

Wasim borrowed some money at 6% per annum simple interest for the first four years 8% per annum for the next 3 years and 10% per annum for a period beyond 7 years at the end of 12 years he earned 5880 at simple interest how much money did he borrow

Answer 1

A=₹5880

Rate of Interest=i (in decimal)

I=Total interest

Principal=P

Accumulated amt=A

time=t

For first 4 years.....

For next 3 years....

I=pit

i=.08 t=4.

i=0.1 t=3

I(1)=0.32p.

I(2)=0.3p

for next 12-7=5 years

I=pit
i=0.06 t=5

l(3)=0.30p

A=p+{I(1)+I(2)+I(3)}

5880=p+p(0.32+0.30+0.30)

5880=p+0.92p

5880=1.92p

p=5880÷1.92

p=₹3062.5