Reply
Honored Contributor
Posts: 18,069
Registered: ‎10-04-2010

we're watching the Price is Right. If you have 4 numbers, how many combos of those 4 numbers can you end up with. I said less than he did, he said 24, I said 16. We tried listing them then went bonkers. We figured for 3 there would be 6 combos. No wonder they can't win the car! LOL

 

Is there a way to figure that out quickly w/o listing them all?

Honored Contributor
Posts: 14,357
Registered: ‎03-09-2010

@qualitygalThe number is 24, but I cheated and Googled for the answer.  I knew it couldn't be just 16, but I had no idea until I looked how to get the answer quickly.

 

There's an explanation on Google -- just not near the top of the listings if you want to see how it was done.  Made sense when I saw it.

Honored Contributor
Posts: 18,069
Registered: ‎10-04-2010

Man! Google had that answer? They have everything don't they! I'll have to look it up, thanks!

Trusted Contributor
Posts: 1,560
Registered: ‎12-31-2013

@qualitygal wrote:

we're watching the Price is Right. If you have 4 numbers, how many combos of those 4 numbers can you end up with. I said less than he did, he said 24, I said 16. We tried listing them then went bonkers. We figured for 3 there would be 6 combos. No wonder they can't win the car! LOL

 

Is there a way to figure that out quickly w/o listing them all?


If you have 4 numbers and you want to know the total combinations that can be made from those 4 numbers, the calculation would be 4x3x2x1 or 24 combinations.  Similarly for 5 it would be 5x4x3x2x1 or 120 combinations.

 

The formula is more complex if you want to know something like how many possible combinations of 4 numbers can be made from a set of 15 numbers (as an example).

Honored Contributor
Posts: 30,109
Registered: ‎03-12-2010

@qualitygal Yes you can google everything.  I just googled in response to your post about the sock.  Here's what I said, 

'what are jokes about losing one sock'.....you wouldn't believe all of the laundry jokes that came up!

 

I google everything.  Unfortunately, it also causes me to get way too many junk emails and calls, but at least for 5 minutes people think I'm smart!  Ha!

Frequent Contributor
Posts: 148
Registered: ‎12-17-2013

4x3x2x1=24

Honored Contributor
Posts: 8,420
Registered: ‎03-09-2010

Re: math people

[ Edited ]

As others have said, it is 4! (4 factorial) which is 4x3x2x1.

Valued Contributor
Posts: 748
Registered: ‎05-24-2011

that made my head hurt! "They promised there would be no math."

Regular Contributor
Posts: 161
Registered: ‎06-14-2010

Re: math people

[ Edited ]

does order matter?

 

Is "4, 3, 2, 1" the same as "1, 2, 3, 4" or are they considered different?

 

If it is a "combination" then order doesn't matter and the answer is 1.

 

If it is a "permutation" then order does matter and the answer is 24.

 

The question actually asked for "combo" so the answer is 1.