Question

Find the largest number which is completely divisible by 28 and 42.

Answer 1

The largest number that is completely divisible by 28 and 42 is HCF of the two numbers.

$\begin{array}{cc}2& 28,42\\ 2& 14,21\\ 3& 7,21\\ 7& 7,7\\ & 1,1\end{array}$
.......[2 Marks]

Hence HCF of 28 and 42 is $2\times 7=14$ ....[1 Mark]