Question

From the yearbook receipts the students council deposited apart of the $1200 in a saving account receiving 9% interest per annum, and the rest in a chequing account receiving 4% per annum. If the total interest received for a year is $88, how much money was deposited in each accounts? 10marks

Answer 1

There was $800 deposited at 9% interest and $400 deposited at 4% interest.

The formula for simple interest is I = prt.  Using our information we have:

88 = x(0.09)(1) + (1200-x)(0.04)(1)
88 = 0.09x + 48 - 0.04x
88 = 0.05x + 48

Subtract 48 from both sides:
88 - 48 = 0.05x + 48 - 48
40 = 0.05x

Divide both sides by 0.05:
40/0.05 = 0.05x/0.05
x = 800
1200 - x = 400