Question

Which of the following represents the prime factorisation of 405?

• A. $3\times 3\times 3\times 3\times 5$
• B. $2\times 3\times 3\times 3\times 5$
• C. $2\times 3\times 3\times 5\times 5$
• D. $3\times 3\times 3\times 5\times 5$

Answer 1

The correct option is A

$3\times 3\times 3\times 3\times 5$

To find: Prime factorisation of 405.

$\begin{array}{cc}3& 405\\ 3& 135\\ 3& 45\\ 3& 15\\ 5& 5\\ & 1\end{array}$

$405=3\times 3\times 3\times 3\times 5$