Prime Factors, HCF & LCMEdexcel IGCSE Maths: Subtopic test
10 questions, 26 marks
Edexcel IGCSE Maths
Prime Factors, HCF & LCM
Total 26 marks
Name
Class
Date
- 1Two garden centres, Greenfield and Rosewood, are ordering matching sets of plant pots and trays. Greenfield orders 360 identical pots and Rosewood orders 252 identical pots.(a)Express 360 as a product of prime factors.[1 mark]
- A
- B
- C
- D
(b)Express 252 as a product of prime factors.[1 mark]- A
- B
- C
- D
(c)What is the highest common factor (HCF) of 360 and 252?[1 mark]- A
- B
- C
- D
Total for question 1: 3 marks
- 2Two lighthouses flash at regular intervals to warn passing ships. Lighthouse A flashes every 18 seconds and Lighthouse B flashes every 24 seconds. Both flash together at exactly 8:00pm.(a)Two lighthouses flash at regular intervals. Lighthouse A flashes every 18 seconds and Lighthouse B flashes every 24 seconds. Find the lowest common multiple (LCM) of 18 and 24.[2 marks](b)Using your answer to part (a), find the next time after 8:00pm that both lighthouses flash together.[2 marks]
Total for question 2: 4 marks
- 3A ribbon factory has two rolls of ribbon, one of length 84 metres and one of length 126 metres, and wants to cut both into equal-length pieces with none left over, then package the pieces into identical boxes.(a)Find the HCF of 84 and 126 using prime factorisation.[3 marks](b)Using the piece length found in part (a), calculate the total number of pieces of ribbon produced from both rolls combined.[3 marks]
Total for question 3: 6 marks
- 4A school is organising three coach trips departing from the same car park at 9:00am. Coach P returns every 30 minutes, Coach Q every 45 minutes and Coach R every 60 minutes. The school also wants to split 90 students into equal groups matching a factor of the LCM.(a)A school is organising three coach trips that depart from the same car park. Coach P returns every 30 minutes, Coach Q returns every 45 minutes and Coach R returns every 60 minutes, all starting together at 9:00am. Find the LCM of 30, 45 and 60 by writing each number as a product of its prime factors.[4 marks](b)At what time will all three coaches next be back at the car park together?[4 marks](c)The school wants to divide the students from three year groups, of sizes 90, 108 and 126, into the largest possible number of equal groups so that each group contains a whole number of students from each of the three year groups. Find the HCF of 90, 108 and 126 using prime factorisation, and state the number of groups formed.[5 marks]
Total for question 4: 13 marks
End of questions