Question

7. A certain amount of money amounts to 35500 in 2 years and to 35750 in three years. Find the principal
and the rate of interest.​

Answer 1

Answer:

Amount = Principal + Simple interest

For two years, The amount is

P*R*2/100+P=35500

2PR/100+P=35500

P*(100+2R)/100=35500-(1)

For three years , The amount is

P*R*3/100+P=35750

3PR/100+P=35750

P*(100+3R/100)=35750-(2)

Subtracting eq. 1 from eq. 2, we get

35750-35500=P((100+3R)/100)-P((100+2R)/100)

250=P*((100+3R-100-2R)100)

250=P*R/100

As we know,

2PR/100+P=35500

Putting the value of PR/100

2*250+P=35500

500+P=35500

P=35000

Also, R

=250/35000*100

=5/7 percent

So

P=35000 rupees

R=5/7 percent