Question

Using prime factorisation method find the HCF and LCM of: (i) 144, 198 (ii) 24, 36, 40 (iii) 30, 72, 432

Answer 1

$$\begin{gathered} i)144=2\times 2\times 2\times 2\times 3\times 3 \\ 198=2\times 3\times 3\times 11 \\ HCF=2\times 3\times 3=18 \\ LCM=2^4\times 3^2\times 11=1584 \\ ii)24=2\times 2\times 2\times 3 \\ 36=2\times 2\times 3\times 3 \\ 40=2\times 2\times 2\times 5 \\ HCF=2\times 2=4 \\ LCM=2^3\times 3\times 5=120 \end{gathered}$$