MovieChat Forums > Brain Games (2011) Discussion > Patterns quiz - not even close

Patterns quiz - not even close

posted 9 years ago by brimfin
2 replies | jump to latest

In the "Patterns" episode, they ask how many different ways you can put on 8 different pieces of clothing. Their choices are 64, 856, 1,680 and 4,380, and they claim the correct answer is 1,680. Not even close! The number of possible permutations using 8 items is 8 X 7 X 6 X 5 X 4 X 3 X 2, which equals 40,320!

Where did they even get 1,680 from? I thought perhaps they were treating the two sock or two shoes as if they always had to be consecutive, but some of the sample drawings they use show the socks and shoes both separated by other articles of clothing, so that wouldn't be the case. They just plain got it wrong.

[–] donnamcooper 9 years ago

Your math is good only if you consider that you could put any of the 8 items on first. They're still assuming that ultimately you will be properly dressed. You wouldn't put your pants on before your underwear or your socks over your shoes. So, to begin, you only have 5 choices. For your second choice, you're down to 7 items and 2 of them must be the shoes, so you again have 5 choices unless your first item was a sock. And they must have also made the assumption that you can't put on your pants if you have shoes on.

[–] rockhut 9 years ago

nice job.