Question

. A businessman invested a total of Rs. 9,000 in two savings accounts. One account earns 8% interest per year and the other earns 10% interest per year. At the end of the first year, the two investments earned a total of Rs. 790 in interest. Find how much he invested on each accounts.

Answer 1

amount invested in the account that earns 10% interest = Rs 3500

amount invested in the account that earns 8% interest =Rs 5500

Explanation:

Two equations can be derived from the question

x + y = 9000 equation 1

0.08x + 0.1y = 790 equation 2

x = amount invested in the account that earns 8% interest

y = amount invested in the account that earns 10% interest

multiply equation 1 by 0.08

0.08x + 0.08y = 720 equation 3

subtract equation 3 from 2

0.02y = 70

divide both sides of the equation by 0.02

y = 70 / 0.02

y = 3500

Substitute for y in equation 1

x + 3500 = 9000

x = 9000 - 3500 = 5500