Light A flashes every 8 seconds.
Light B flashes every 20 seconds.
Both lights flash at the same time.
Work out how long it will take for both lights to flash at the same time again.
Practise Edexcel IGCSE Maths Prime Factors, HCF and LCM with exam-style questions for IGCSE Maths. 16 questions, matched to the Edexcel IGCSE Maths (4MA1) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.