-
pappueshwar
- Master | Next Rank: 500 Posts
- Posts: 234
- Joined: Fri Oct 01, 2010 7:28 pm
- Location: chennai
- Thanked: 5 times
- Followed by:4 members
Prompt: From a drawer containing black, blue and gray solid-color socks, including at least three socks of each color, how many matched pairs can be removed?
Statement #1: The drawer contains 11 socks.
Here are the only two possibilities:
Case One:
color #1 = 5 socks ---> 2 pairs
color #2 = 3 socks ---> 1 pair
color #3 = 3 socks ---> 1 pair
TOTAL = 4 pairs
Case One:
color #1 = 4 socks ---> 2 pairs
color #2 = 4 socks ---> 2 pairs
color #3 = 3 socks ---> 1 pair
TOTAL = 5 pairs
Because two cases are possible, we don't know how many pairs, 4 or 5. Statement #1 is insufficient.
Statement #2: The drawer contains an equal number of black and gray socks. .
There could be ten socks or a million socks. We have no idea given this piece of information. Statement #2 is insufficient.
Combined Statements #1:
Here are the only two possibilities:
Case One:
blue = 5 socks ---> 2 pairs
black = 3 socks ---> 1 pair
grey = 3 socks ---> 1 pair
TOTAL = 4 pairs
Case One:
black = 4 socks ---> 2 pairs
grey = 4 socks ---> 2 pairs
blue = 3 socks ---> 1 pair
TOTAL = 5 pairs
Even with both statements, we don't know how many pairs, 4 or 5. Combined, the statements are insufficient.
Answer = E
Here's another DS question about socks.
https://gmat.magoosh.com/questions/1038
When you submit your answer to that question, the following page will have a video explanation.
Does all this make sense? Please let me know if you have any further questions.
Mike
