SOLUTION: HELP! I have tried several different ways to set up this problem, but I can't get it right! I don't know what formula to use in order to solve it. Melinda’s lights went ou

Algebra ->  Probability-and-statistics -> SOLUTION: HELP! I have tried several different ways to set up this problem, but I can't get it right! I don't know what formula to use in order to solve it. Melinda’s lights went ou      Log On


   



Question 140091: HELP! I have tried several different ways to set up this problem, but I can't get it right! I don't know what formula to use in order to solve it.
Melinda’s lights went out. She has 3 pairs of red socks in her drawer, 2 pairs of black socks, and 5 pairs of white socks. What is the minimum number of pairs she must remove from the drawer to ensure that she has a pair of each color?
Thank you!

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
not sure about a formula __ this is like a thought experiment

she needs a pair of each color, so what is the BEST case?
__ she picks 3 pairs, one of each color

but with no lights, she has to pick enough to be SURE she has one of each color
__ so what's the WORST case?
__ she picks 5 pairs, all white
__ then she picks 3 more pairs, all red
__ finally, she picks a black pair

so, to be SURE, she has to pick 9 pairs