Question

Match the numbers to the product of its prime factors.

• A. 2 × 2 × 3 × 13
• B. 2 × 2 × 5 × 5
• C. 3 × 37
• D. 2 × 2 × 5 × 7

Answer 1

The prime factorisation of 140 is :
$\begin{array}{cc}2& 140\\ 2& 70\\ 5& 35\\ 7& 7\\ & 1\end{array}$
Hence, 140 = $2\times 2\times 5\times 7.$

The prime factorisation of 156 is :
$\begin{array}{cc}2& 156\\ 2& 78\\ 3& 39\\ 13& 13\\ & 1\end{array}$
Hence, 156 = $2\times 2\times 3\times 13.$

The prime factorisation of 100 is :
$\begin{array}{cc}2& 100\\ 2& 50\\ 5& 25\\ 5& 5\\ & 1\end{array}$
Hence, 100 = $2\times 2\times 5\times 5.$

The prime factorisation of 111 is :
$\begin{array}{cc}3& 111\\ 37& 37\\ & 1\end{array}$

Hence, 111 = $3\times 37.$