Mathematics for IGCSE & O level - Number (Section 2 - No. 17)

What is the HCF of 72 and 108?

The prime factorization of 72 = 2^3 * 3^2. The prime factorization of 108 = 2^2 * 3^3. HCF = 2^2 * 3^2 = 4 * 9 = 36.