Don't be tricked!
To please their children, Mr and Mrs Tan bought socks of their children's favourite colours. They bought 10 socks for Benedict, 20 socks for Bob, 30 socks for Brenda, 40 socks for Brian and 50 socks for Billy.
Unfortunately, there was a blackout one night but Brenda wants to grab a pair of socks. Although she may not get her favourite socks, she at least wants a pair of socks of the same colour. What is the MINIMUM number of socks she needs to pull out to be ABSOLUTELY certain of this?
The answer is 6.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
The number of socks of each colour is a distractor, hence the title 'don't be tricked'. Upon grabbbing 5 socks, the worst case scenario is for Brenda to get eaxctly ONE sock of each colour. Of course, if she already has a pair of matching socks, the job is already done. But even with the worst case scenario, Brenda only needs to pull out a 6th sock as its colour is bound to be the same as one of the 5 socks she already has.