Find the highest common factor (HCF) of and .

Answer and explanation

Correct answer: C.

  1. Step 1: Prime factors give and .
  2. Step 2: The common factors multiply to .
Answer
.
Why not the others: is what you get if you give the lowest common multiple. is what you get if you multiply the numbers. is what you get if you assume the numbers share no factor.

Practise more Number, Fractions and Ratio.

Free questions with an explanation for every one, and full timed GCE O/L Mathematics (Sri Lanka) mock tests.