At demeter deals, the cost of 3 apples and 4 bananas is $4.23, and the cost of 5 apples and 7 bananas is $7.16. at these prices, what would be the cost of 1 apple and 1 banana?

Let the cost of 1 apple= $x

and the cost of 1 banana=$ y

The cost of 3 apples and 4 bananas is $4.23.

i.e.

3x+4y=4.23(1)

and the cost of 5 apples and 7 bananas is $7.16.

i.e.

5x+7y=7.16(2)

On multiplying equation (1) by 5 and equation (2) by 3 and subtracting equation (1) from equation (2) we have:

y=0.33

and putting the value of y in equation (1) we have:

x=2.91

Hence, we have: cost of 1 apple = $ 2.91

and cost of 1 banana= $ 0.33

This means that the combined cost of 1 apple and 1 banana is:

= $ (2.91+0.33)

= $ 3.24

2/3=10/15

1/5=3/15

10+3=13/15

2 13/15 is the answer