Question

you have 5 friends who want to go to the concert with you, but you only have three etra tickets

Answer 1

Pick 3 of your best friends.

Answer 2

give the tickets to them or buy another 1 :)

Answer 3

tell 2 friends to go on a scavenger hunt for the last ticket

Answer 4

Let them play rock, paper, scissors XD

So it doesn't look like you value one friend more than the other.