Answer:
1/4 & 1
Solution:
1/2 * 1/2 = (1*1)/(2*2)
1/2 + 1/2 = (1+1)/(2) = 2/2 = 1
You divide the top by the battle
Method OneYour calculator might be able to do this. Mine does it like this.
6
nCr
2
=
15
Method 2You could simply set up 6C2
This gives you
Method ThreeYou only have to do this a couple of times to see how the cancellation works.

After all the cancellation takes place you have
6*5/2 = 15