Question

find HCF of 90 and 144 by prime fsctorisation method

Answer 1

$$\begin{gathered} \mathrm{Prime}\mathrm{factorisation}\mathrm{of}90\mathrm{and}144: \\ 90=2\times 3\times 3\times 5 \\ 72=2\times 2\times 2\times 3\times 3 \\ \mathrm{HCF}(90,72)=2\times 3\times 3=18 \end{gathered}$$