Question

Please help !! Picture provided !!!

Answer 1

Method One
Your calculator might be able to do this. Mine does it like this.
6
nCr
2
=
15

Method 2
You could simply set up 6C2

This gives you

`(n!)/((n- r)! r!) = (6!)/((6 - 2)!2!) = (6!)/(4! 2!) = (6*5)/(2*1) = 15`

Method Three
You only have to do this a couple of times to see how the cancellation works.


`(6!)/(4!2!) = \frac{6*5*\st{4*3*2*1}}{4*3*2*1 * 2*1}`
After all the cancellation takes place you have
6*5/2 = 15