How many ways are there to split a group of 10 students into two groups of 5 students each? (The order of the groups does not matter)  Choices.
A) 104  B) 126  C) 148  D) 172  E) 216
10C5 = 252   If we consider these groups, each group will be counted twice.   The number of ways to choose 2 groups of 5 is  252/2= 
<gadget id="calculator"> 252/2</gadget>
<output>126</output>
126   The answer is 126.
<result>B</result>
How many ways are there to split a group of 10 students into two groups of 5 students each? (The order of the groups does not matter)