How many combinations of players can a coach have if he needs to pick 2 out of a total of 4? what is a simpler way to find out
To find how many combinations of 2 players can be chosen from 4, you’re dealing with combinations (order doesn’t matter).
Simple Method (Combination Formula)
Use:
(nr)=n!r!(n−r)!\binom{n}{r}=\frac{n!}{r!(n-r)!}(rn)=r!(n−r)!n!
Here:
- n=4n=4n=4 (total players)
- r=2r=2r=2 (players to pick)
(42)=4!2!⋅2!=4⋅32⋅1=6\binom{4}{2}=\frac{4!}{2!\cdot 2!}=\frac{4\cdot 3}{2\cdot 1}=6(24)=2!⋅2!4!=2⋅14⋅3=6
Even Simpler Way (No Formula Needed)
Just list them:
- Player 1 & Player 2
- Player 1 & Player 3
- Player 1 & Player 4
- Player 2 & Player 3
- Player 2 & Player 4
- Player 3 & Player 4
That’s 6 combinations.
Quick Trick to Remember
For small numbers:
- Think: “How many unique pairs can I make?”
- Or use:
n(n−1)2\frac{n(n-1)}{2}2n(n−1)
So:
4⋅32=6\frac{4\cdot 3}{2}=624⋅3=6
This shortcut works anytime you’re picking 2 items from a group. Final Answer: 6 combinations