Me & 4 friends spent a total of $25 for a cake & 3 milkshakes. If the cost of the cake was $13, how much was each shake?
- $4, because 25 – 13 = 12 and 12 ÷ 3 = 4.
- $1, because 4 x 3 = 12 and 13 – 12 = 1
- $9, because 13 + 3 = 16 and 25 – 16 = 9
- $3, because 25 – 13 = 12 and 12 ÷ 4 = 3