Difference between revisions of "2010 AMC 10B Problems/Problem 3"

(Video Solution)
 
(3 intermediate revisions by 3 users not shown)
Line 5: Line 5:
  
 
<math>
 
<math>
\mathrm{(A)}\ 3
+
\textbf{(A)}\ 3
 
\qquad
 
\qquad
\mathrm{(B)}\ 4
+
\textbf{(B)}\ 4
 
\qquad
 
\qquad
\mathrm{(C)}\ 5
+
\textbf{(C)}\ 5
 
\qquad
 
\qquad
\mathrm{(D)}\ 8
+
\textbf{(D)}\ 8
 
\qquad
 
\qquad
\mathrm{(E)}\ 9
+
\textbf{(E)}\ 9
 
</math>
 
</math>
  
 
== Solution ==
 
== Solution ==
After you draw <math>4</math> socks, you can have one of each color, so (according to the pigeonhole principle), if you pull <math>\boxed{\mathrm{(C)} 5}</math> then you will be guaranteed a matching pair.
+
After you draw <math>4</math> socks, you can have one of each color, so (according to the [[pigeonhole principle]]), if you pull <math>\boxed{\textbf{(C)}\ 5}</math> then you will be guaranteed a matching pair.
 +
 
 +
==Video Solution==
 +
https://youtu.be/wAnVjpaNFIA
 +
 
 +
-Education, the Study of Everything
 +
 
 +
==Video Solution==
 +
https://youtu.be/uAc9VHtRRPg?t=130
 +
 
 +
~IceMatrix
 +
 
 +
==See Also==
 +
{{AMC10 box|year=2010|ab=B|num-b=2|num-a=4}}
 +
{{MAA Notice}}

Latest revision as of 16:59, 1 August 2022

Problem

A drawer contains red, green, blue, and white socks with at least 2 of each color. What is the minimum number of socks that must be pulled from the drawer to guarantee a matching pair?

$\textbf{(A)}\ 3 \qquad \textbf{(B)}\ 4 \qquad \textbf{(C)}\ 5 \qquad \textbf{(D)}\ 8 \qquad \textbf{(E)}\ 9$

Solution

After you draw $4$ socks, you can have one of each color, so (according to the pigeonhole principle), if you pull $\boxed{\textbf{(C)}\ 5}$ then you will be guaranteed a matching pair.

Video Solution

https://youtu.be/wAnVjpaNFIA

-Education, the Study of Everything

Video Solution

https://youtu.be/uAc9VHtRRPg?t=130

~IceMatrix

See Also

2010 AMC 10B (ProblemsAnswer KeyResources)
Preceded by
Problem 2
Followed by
Problem 4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 10 Problems and Solutions

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png