Try the fastest way to create flashcards
Question

A drawer of socks contains seven black socks, eight blue socks, and nine green socks. Two socks are chosen in the dark. a. What is the probability that they match? b. What is the probability that a black pair is chosen?

Solution

Verified
Step 1
1 of 4

Fundamental counting principle: If one event can occur in $m$ ways and a second event can occur in $n$ ways, the number of ways the two events can occur in sequence is then $m\cdot n$.

Definition permutation (order is important):

$P_{n,r}=\dfrac{n!}{(n-r)!}$

Definition combination (order is not important):

$C_{n,r}=\dfrac{n!}{r!(n-r)!}$

with $n!=n\cdot (n-1)\cdot ...\cdot 2\cdot 1$.

Recommended textbook solutions

Probability and Statistics for Engineers and Scientists

9th EditionISBN: 9780321629111 (4 more)Keying E. Ye, Raymond H. Myers, Ronald E. Walpole, Sharon L. Myers
1,204 solutions

Mathematical Statistics and Data Analysis

3rd EditionISBN: 9780534399429John A. Rice
809 solutions

The Practice of Statistics for the AP Exam

5th EditionISBN: 9781464108730Daniel S. Yates, Daren S. Starnes, David Moore, Josh Tabor
2,433 solutions

Statistics and Probability with Applications

3rd EditionISBN: 9781464122163Daren S. Starnes, Josh Tabor
2,555 solutions