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Junior Cycle Maths: Factors, multiples & primes

How often Factors, multiples & primes comes up on the Maths papers, every year it was asked, and questions to try.

HL Asked on 1 of the last 5 Higher Level papers, most recently in 2024.

OL Asked on 3 of the last 5 Ordinary Level papers, most recently in 2026. most years

Factors, multiples & primes, Higher Level(7 marks)

Quick ones on Factors, multiples & primes.

(a)Highest common factor (HCF) of 36 and 60?

(b)Two buses leave a stop together at 09:00, one every 12 min and one every 18 min. When do they next leave together?

(c)Which of these numbers is prime?

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(a) 12

(b) 09:36

(c) 97

Your turn: Higher Level questions on Factors, multiples & primes.

Higher Level

Asked on 1 of the last 5 Higher Level papers, most recently in 2024.

Links open the State Examinations Commission’s paper for that year.

Asked on 3 of the last 5 Ordinary Level papers, most recently in 2026. most years

Links open the State Examinations Commission’s paper for that year.

Factors, multiples & primes, 2 marks

What is the highest common factor (HCF) of 12 and 18?

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Factors of 12: 1, 2, 3, 4, 6, 12. Factors of 18: 1, 2, 3, 6, 9, 18. The biggest number in both lists is 6. 36 is a common multiple, not a factor.

Factors, multiples & primes, 2 marks

Which of these is a prime number?

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A prime has exactly two factors: 1 and itself. 27 = 3 × 9 and 39 = 3 × 13, but only 1 and 29 divide into 29.

Factors, multiples & primes, 2 marks

What is the lowest common multiple (LCM) of 4 and 6?

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Multiples of 4: 4, 8, 12 … Multiples of 6: 6, 12 … The first number in both lists is 12. 24 is a common multiple but not the lowest.