Melons cost QR1.5 each and apples cost QR3.75 per kilogram. A man buys apples and melons at the supermarket. Write a formula to describe the total cost of his purchase.

Investigate how many melons and how many kilograms of apples he could buy for QR30.

**QR is a currency :)

1 answer

First you must define your variables.
In full sentence form define
apples ---> a
melons ---> m

then Cost = 3.75a + 1.5m

second equation:
3.75a + 1.5m ≤ 30
multiply this equation by 4

15a + 6m ≤ 120 , dividing by 3
5a + 2m ≤ 40

2m ≤ 40 - 5a

For m to be a whole number, the right side of the above statement has to be even, so a must be an even number
0 ≤ a ≤ 8

so give a values of 0, 2, 4, 6, and 8