Two automated irrigation pumps, Pump P and Pump Q, both start at the same time.
Pump P runs every 20 minutes.
Pump Q runs every 28 minutes.
Both pumps start together at 4:50 pm.
At what time will both pumps next start at the same time?
59 exam-style questions on Edexcel GCSE Maths Prime Factors, HCF and LCM. Each one has a worked solution and a mark scheme showing where the marks go.