# Data Help!!! Counting Techniques

• Mar 3rd 2008, 03:08 PM
wikji
Data Help!!! Counting Techniques
A class has 12 students. In how many different ways can the students be put into groups of 3?

• Mar 3rd 2008, 03:53 PM
roy_zhang
Since the order of students within each group does not matter, we use combination as:

$\binom{12}{3}\binom{9}{3}\binom{6}{3}\binom{3}{3}= 369600$
• Mar 3rd 2008, 04:33 PM
Plato
Quote:

Originally Posted by wikji
A class has 12 students. In how many different ways can the students be put into groups of 3?
The answer in this case is $\frac{{\left( {12} \right)!}}{{\left( {3!} \right)^4 \left( {4!} \right)}}=15400$