BdMO National Secondary 2007#10

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samiul_samin
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BdMO National Secondary 2007#10

Unread post by samiul_samin » Sat Feb 23, 2019 8:57 am

A drawer in a darkened room contains $100$ black socks, $80$ blue socks, $60$ red socks and $40$ purple socks. A youngster selects socks one at a time from the drawer but is unable to see the color of the socks drawn. What is the smallest number of socks that must be selected to guarantee that the selection contains at least $10$ pairs? [A pair of socks = $2$ socks of the same color.]

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samiul_samin
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Re: BdMO National Secondary 2007#10

Unread post by samiul_samin » Sat Feb 23, 2019 8:59 am

Hint
PHP
Answer
$23$
Problem Source
AHSME $1986$ Problem $17$
Solution source

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