Question

In what time period will ₹1250 becomes an amount of ₹1488.77 at a compound

interest of 6% per annum?​

Answer 1

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 Rs. 500/- and rate of Interest is 50% p.a.