If 4 glasses cost 3 pounds, how much is it per glass?

Let us solve this problem algebraically:

4 glasses = £3

1 glass = x

Cross multiply: 4 * x = 4x and 3 * 1 = 3

4x = 3

4x/4 = 3/4 (get x on it own by dividing by 4 on both sides)

x = 0.75

So, it would cost £0.75 a glass.

75 p each