It takes 5 machines 6 hours to produce 1000 DVDs
Work out how long it would take 4 machines to produce 1000 DVDs.
Hence, work out how long it would take 10 machines to produce 1500 DVDs.
189 exam-style questions on OCR GCSE Maths Direct and Inverse Proportion. Each one has a worked solution and a mark scheme showing where the marks go.