Question

If a certain sum amounts to Rs 515 in 3 years and to Rs 530 in 6 years, find the rate of interest.​

Answer 1

Answer:

Step-by-step explanation:

We know that,

(1) Interest = Principal × Rate of interest × Time

(2) Amount = Principal + Interest

Let principal = Rs x

For amount = Rs 515,

Using (2), we get:

Interest = 515 - x

Using (1), we get:

Rate of interest =  ( 515 − x )/ 3 x

Similarly, for amount = Rs 530,

Rate of interest =  ( 530 − x )/ 6 x

Equating both the rates of interest we have,

x = 500

Hence, rate of interest =  

15 /500 × 3

=  1 /100

= 1%