Question

Find the sum and rate of simple interest if its amount is 7200Rs in 5 years and to 8064Rs in 8 years

Answer 1

The principal is  6624 Rs and rate is 4.34%.

Step-by-step explanation:

• Since, we know that the amount 7200 Rs is reached to 8064 Rs in 3 years.

It means that;

• S.I for 3 years = (8064 - 7200) = 864 Rupees

So,    S.I. for 1 year =$\dfrac{864}{3}$ = 288 Rs.

       S.I. for 5 years = $288 \times 5$ = 1440 Rs

Now, we can find out the principal as;

• Principal = 8064 - 1440 = 6624 Rs

Thus, we can find out the rate as,

• $r = \dfrac{100 \times 1440}{6624 \times 5}$

              r = 4.34%

Thus, the principal is  6624 Rs and rate is 4.34%.