Answer: 21
Step-by-step explanation: This is a combination of 7 objects taken 5 at a time
nCr = n! / r! * (n - r)!
7C5 = 7! / (5! (7-5)!)
= 7! /(5! 2!)
= (7*6*5*4*3*2*1)
-----------------------
5*4*3*2*1 * 2*1
Canceling
= 7*6/ (2*1)
= 21
