SOLUTION: 2. How many ways are there to arrange 10 students in two lines? (a line must have at least 1 student)I used nCr on a TI 84+ Calculator and got 28, but i have a feeling I am rather

Algebra ->  Permutations -> SOLUTION: 2. How many ways are there to arrange 10 students in two lines? (a line must have at least 1 student)I used nCr on a TI 84+ Calculator and got 28, but i have a feeling I am rather      Log On


   



Question 750507: 2. How many ways are there to arrange 10 students in two lines? (a line must have at least 1 student)I used nCr on a TI 84+ Calculator and got 28, but i have a feeling I am rather mistaken. How do I go about solving this?
Answer by FrankM(1040) About Me  (Show Source):
You can put this solution on YOUR website!
I am going to hazard an intelligent approach here and offer 9*10!
If you simply asked how to line up 10 people, the answer would be 10! different ways to line up. Now, look at a line of ten and there are 9 places to declare the second line starts there, so to account for all 9 possibilities in every line, multiplying by 9 should suffice.