Answer
$240=2^4\times3\times5$
Work Step by Step
$\ \ 240$
$\swarrow\searrow$
$2\ \ \ 120$
$\ \ \ \ \swarrow\searrow$
$\ \ \ \ 2\ \ \ \ \ \ \ 60$
$\ \ \ \ \ \ \ \ \ \ \swarrow\searrow$
$\ \ \ \ \ \ \ \ \ 2\ \ \ \ \ \ \ 30$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \swarrow\searrow$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 2\ \ \ \ \ \ \ 15$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \swarrow\searrow$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 3\ \ \ \ \ \ \ 5$