Question

A sum of Rs 1,250 amounts to Rs 1,550 in 4 years at a specific simple interest rate.
What is the rate of interest?

Answer 1

Answer:

So, the sum is Rs. 500/- and rate of Interest is 50% p.a.

Step-by-step explanation:

Let x be the sum of money and y be the rate of Interest

Using formula for Simple Interest, we have,

x + x * 3 * y / 100 = 1250

i.e. x + 0.03xy = 1250 — (i)

Also, we have,

x + x * 4 * y / 100 = 1500

i.e. x + 0.04xy = 1500 — (ii)

Subtracting, equation (i) from (ii), we get,

0.01xy = 250

i.e. xy = 25000 — (iii)

Substituting equation (iii) in (i), we get,

x + 0.03 * 25000 = 1250

i.e. x + 750 = 1250

i.e. x = 500 — (iv)

Substituting equation (iv) in (iii), we get,

500y = 25000

y = 50

So, the sum is So, the sum is Rs. 500/- and rate of Interest is 50% p.a.

Answer 2

Answer:

6%

Step-by-step explanation:

Amount=sum+SI

1550=1250+1250*4*r/100

1550=1250(1+4*r/100)

31=25((25+r)/25)

r=6%