Factors, multiples, primes, HCF and LCM

Question 1 of 10

The only even prime number is

Question 2 of 10

The prime factorisation of 12 is 2 × 2 × 3.

Question 3 of 10

Find the LCM of 40 and 64.

Question 4 of 10

Bells ring at intervals of 12 minutes and 8 minutes. They ring together at 8:00 a.m. (a) Find the LCM of 12 and 8. (b) At what time will they next ring together? Show your working.

Question 5 of 10

Bells ring at intervals of 12 minutes and 45 minutes. They ring together at 8:00 a.m. (a) Find the LCM of 12 and 45. (b) At what time will they next ring together? Show your working.

Question 6 of 10

Find the LCM of 50 and 90.

Question 7 of 10

The largest prime factor of 24 is ___.

Question 8 of 10

Find the LCM of 45 and 72.

Question 9 of 10

The largest prime factor of 60 is ___.

Question 10 of 10

Find the HCF of 18 and 36.