Question

Determine the prime factorisation of 20570.

• A. 2 x 5 x 11 x 17 x 17
• B. 2 x 3 x 11 x 11 x 17
• C. 2 x 5 x 11 x 11 x 17
• D. 2 x 5 x 5 x 11 x 17

Answer 1

The correct option is C 2 x 5 x 11 x 11 x 17

20570 can be factorised as following:

$\begin{array}{cc}2& 20570\\ 5& 10285\\ 11& 2057\\ 11& 187\\ 17& 17\\ & 1\end{array}$
Thus, 20570 = 2 x 5 x 11 x 11 x 17