Question 508299
Use following formula
nCr = n! /r!(n-r)!

Where
n=8, r=4
Total Combinations = 8C4 = 8!/4!(8-4)!
Total Combinations = 8C4 = 8!/4!(4)!
Total Combinations = 8C4 = 8*7*6*5*4!/4*3*2*1*4!
Cancel out 4!
Total Combinations = 8C4 = 8*7*6*5/4*3*2*1
Total Combinations = 8C4 = 1680/24
Total Combinations = 8C4 = 70