A shade of green paint is made by mixing yellow paint and blue paint in the ratio 5:2. Mel has 30 litres of yellow paint and 9 litres of blue paint. what is the maximum amount of green paint she can make?

31.5 litres

Step-by-step explanation:

If Mel uses all 30 litres of yellow paint, then:

5 / 2 = 30 / x

5x = 60

x = 12

Mel would need 12 litres of blue paint, but she only has 9 litres. So the amount of yellow paint she needs is:

5 / 2 = x / 9

2x = 45

x = 22.5

Mel will use 22.5 litres of yellow paint with 9 litres of blue paint to make a total of 31.5 litres of green paint.