Question

If JAke has 10 white socks, 8 black socks, and 6 gray socks, how many does he need to take out to ensure that he he will get a pair of white socks?

Answer 1

$The\ probability\ to\ get\ a\ white\ sock = \frac{10 }{10 + 8 + 6}X\frac{9 }{9 + 8 + 6} = \frac{10}{24}X\frac{9}{23}=\frac{90}{552}\\\\= \frac{ \frac{90}{90} }{ \frac{552}{90} }= \frac{1}{6.13} \\\\it\ means\ that\ Jake\ need\ to\ take\ out\ 7\ socks\ to\ get\ a\ white\ pair\ of\\socks.$