GK 2019 Q20
20. Liam spent all his money buying 50 soda bottles at the corner shop for £1 each. He sold each bottle at the same higher price. After selling 40 bottles, he had £10 more than he started with. He then sold all the remaining bottles. How much money did Liam have once all the bottles were sold?
- A £70
- B £75
- C £80
- D £90
- E £100
Grey Kangaroo 2019, Question 20. © UK Mathematics Trust. Original paper on ukmt.org.uk
Answer: B £75
Liam spent 50 × £1 = £50 buying the bottles. After selling 40 bottles he had £(50 + 10) = £60. Therefore he sold each bottle for £60 ÷ 40 = £1.50. Hence, after selling all 50 bottles, he then had 50 × £1.50 = £75.
Solution © UK Mathematics Trust, from the GK 2019 solutions.