I have a habit of getting up before the sun rises. My socks are all mixed up in the drawer, which contains 20 blue and 18 black socks. I reach into the drawer and grab some socks in the dark. How many socks minimum do I need to take from the drawer to be sure that I have a matched pair?
A) 18 socks
B) 21 socks
C) 2 socks
D) 3 socks
E) 19 socks

Question

I have a habit of getting up before the sun rises. My socks are all mixed up in the drawer, which contains 20 blue and 18 black socks. I reach into the drawer and grab some socks in the dark. How many socks minimum do I need to take from the drawer to be sure that I have a matched pair? ​
A) 18 socks
B) 21 socks
C) 2 socks
D) 3 socks
E) 19 socks

Quizplus · Accepted Answer

The worst case scenario is that you keep picking up socks of different colors until you have 17 blue socks and 17 black socks. At this point, the next sock you pick up will complete a pair, so you only need to take one more sock for a total of 3 socks. Therefore, the minimum number of socks you need to take from the drawer to be sure you have a matched pair is 3.

I Have a Habit of Getting Up Before the Sun