Question

Find the sum invested at 10% compounded annually, on which the interest for first year plus for the interest for third year amount to rs 1768

Answer 1

${\mathfrak{\red{\huge{Answer}}}}$

Let the sum = rs.100

Rate= 10%

Time= 1year

now: I= (p*r*t)/100 = (100*10*1)/100

= rs.10

Amount for the 1st yr= 100+10 = 110

I for the 2nd yr= (110*10*1)/100 = rs.11

Amount for the 2nd yr= 110+11= rs.121

I for the 3rd yr= (121*10*1)/100 = rs.12.1

now I for the 1st yr+I for the 3rd yr = 10*12.1= rs.22.1

Principal= rs.100

and I for the 1st yr+i for the 3rd yr= rs. 1768 (given)

Principal= (100*1768)/22.1 = rs. 8000.

Answer 2

Answer:

Step-by-step explanation:

Let the sum = rs.100

Rate= 10%

Time= 1year

now: I= (p*r*t)/100 = (100*10*1)/100

= rs.10

Amount for the 1st yr= 100+10 = 110

I for the 2nd yr= (110*10*1)/100 = rs.11

Amount for the 2nd yr= 110+11= rs.121

I for the 3rd yr= (121*10*1)/100 = rs.12.1

now I for the 1st yr+I for the 3rd yr = 10*12.1= rs.22.1

Principal= rs.100

and I for the 1st yr+i for the 3rd yr= rs. 1768 (given)

Principal= (100*1768)/22.1 = rs. 8000.