A brand of shampoo is available in two different bottles.
900 ml for £k£k£k
400 ml for £2.50 £2.50\,£2.50
Work out, in terms of kkk, which bottle offers the best value for money. You must show your working.
84 exam-style questions on Eduqas GCSE Maths Best Buy Questions. Each one has a worked solution and a mark scheme showing where the marks go.