Paying the bill
Gill and I went out to lunch. We agreed to split the total cost equally. How much did I owe Gill?
Age
11 to 14
Challenge level
Problem
Gill is 18 this year. She and I went to a restaurant for lunch to celebrate her birthday.
The bill for lunch for the two of us came to £25.50.
Gill paid the bill by credit card and I left a £2.50 tip in cash.
We agreed to split the total cost equally.
How much did I owe Gill?
Student Solutions
Answer: £11.50
The lunch bill and tip total £28, so Gill and I should both pay £14 each.
Gill has paid £25.50, so she has paid £25.50 - £14 = £11.50 too much.
So I should give her £11.50, and then I will have paid £2.50 + £11.50 = £14