Problem Solving

Q: George's drawer has 10 loose black socks, 15 loose blue socks, and 8 loose white socks. if George takes socks out of the drawer at random, how many would he need to take out to be sure that the removed socks include at least one matching pair ?

a) 3

b)4

c)9

d)15

e)31

Source:Kaplan

I have a question regarding this problem. The answer given to this question is 4. But even if we get a pair of socks of the same color, how can we be sure that the two socks make a pair. For example, it's possible that both are of left foot or both are of right foot, so how does both make a pair. For a pair of socks we need one sock for the right foot and the other sock for the left foot. So how can we be sure that the two socks of same color are one for the right foot and the other for the left foot.

Or, is there some special meaning of the word ' loose socks' ? Are loose socks some special type of socks that have no left-right difference ? What am I missing ? Please advice.

Hi Brent,

Yes, there has been an error. It's 4 which I have corrected. Though it's true that there are no distinct marks specifying left or right socks, we can distinguish left or right sock from the shape of the sock itself. Nevertheless, if the basic idea was to get a pair of socks of same color, then left-right distinction is irrelevant

Thanks!

STEVEN SPIELBERG wrote:Q: George's drawer has 10 loose black socks, 15 loose blue socks, and 8 loose white socks. if George takes socks out of the drawer at random, how many would he need to take out to be sure that the removed socks include at least one matching pair ?

a) 3

b)4

c)9

d)15

e)31

Source:Kaplan

I have a question regarding this problem. The answer given to this question is 4. But even if we get a pair of socks of the same color, how can we be sure that the two socks make a pair. For example, it's possible that both are of left foot or both are of right foot, so how does both make a pair. For a pair of socks we need one sock for the right foot and the other sock for the left foot. So how can we be sure that the two socks of same color are one for the right foot and the other for the left foot.

Or, is there some special meaning of the word ' loose socks' ? Are loose socks some special type of socks that have no left-right difference ? What am I missing ? Please advice.

Such Questions has appeared in GMAT numerous times and the question only has to be attacked considering that a sock for left leg will be same as for right leg. Since the question doesn't specify any dictiction between the two so certainly we don't have to involve our own perception and get confused here.

The answer is straight 4 which I hope you have got

The KEY is to look for worst possible scenario and still make sure that the pair has been picked (favorable outcomes has been achieved)