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November 28, 2015
Posted by **kaykay** on Saturday, March 26, 2011 at 6:04pm.

- math -
**MathMate**, Sunday, March 27, 2011 at 9:34amThe pascal triangle can be used to solve counting problems.

Let's say we have 6 students and we need to choose one student to do a choir. There are six ways to make the single choice.

If we need two students to do the play, we have 6 choices for the first student, and 5 for the second to make 30 choices. Out of the 30 choices, we have made each choice twice, because we could have chosen students A & B and another time B & A. So there are really 15 choices.

If we continue this way, we would come up with the numbers 6, 15, 20, 15, 6 for the number of ways of choosing 1, 2, 3, 4 and 5 students respectively.

If we add the single choices of choosing no students or all of the students, we have the complete 6th line of the Pascal's triangle of:

1 6 15 20 15 6 1