IMC 2006 Q10
10. 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?
- A £11
- B £11.50
- C £12
- D £12.50
- E £13
Intermediate Mathematical Challenge 2006, Question 10. © UK Mathematics Trust. Original paper on ukmt.org.uk
Answer: B £11.50
The lunch bill and tip total £28, so Gill and her friend should pay £14 each. As Gill has paid £25.50, she should now receive £25.50 − £14, that is £11.50.
Solution © UK Mathematics Trust, from the IMC 2006 solutions.