Monday Math Problems Are Imminent!

February 2, 2010

This happened on Facebook today:

facebook.jpg

(By the way, I typically accept Facebook requests from anyone who appears to be using a real name and photo and who is not a foreign man with poor English skills seeking an American lover/green card).

I think a math problem per day might be a bit much, but a math problem a week I can do (thus making the educational content of the blog 16.67% mathematical and 83.33% orthographical).

So, here’s the first one! (It’s Tuesday, but the next one will be on Monday, for alliterative reasons. Unlike the Spelling Word of the Day, instead of posting the answer after the jump, I’m going to re-post the problem, with its explanation, on Friday. So feel free to beat me to it in the comments!)

This Week’s Math Problem:

You are a player who intends to schedule one date every day of the week, plus an extra on Saturday. If you have already made plans for Sunday through Wednesday, and have an additional 10 people on a waiting list to go out with you, how many different social schedules could you arrange for the week?

Posted by jen | Filed Under Monday Math Problems 

Comments

13 Responses to “Monday Math Problems Are Imminent!”

  1. soce on February 2nd, 2010 9:46 pm

    10 chose 4?

  2. Dan Toma on February 2nd, 2010 9:47 pm

    My guess is 5,040 different social schedules could be arranged for the week.

  3. soce on February 2nd, 2010 9:55 pm

    Sorry what I meant is 10 * 9 * 8 * 7.

  4. jen on February 2nd, 2010 10:20 pm

    You might be correct! Next week’s is much harder (it’s already queued up to go!)

  5. Camilo North on February 2nd, 2010 10:39 pm

    I got 5040 as well. That many 4-person permutations out of 10 possible people, or something.

    Half that if we don’t care about the order of the Saturday dates. Say, if you schedule the dates at the same time, then have to come up with excuses to run back and forth between the dates as part of Wacky Comedic Hijinks.

  6. StJ on February 2nd, 2010 11:04 pm

    I think you need to specify whether you can have more than one date with the same person. And, btw, please stop using my life as fodder for your problems!

  7. jen on February 2nd, 2010 11:28 pm

    Camilo, I think it’s inherent in the problem that the order of the Saturday dates matters.

    StJ, no, you can’t have more than one date with the same person. I suppose I could’ve said that, but I think the idea is that you’re making a schedule in advance, so you’d be pretty unlikely to schedule a second date before having a first one ;)

  8. Dominique on February 2nd, 2010 11:32 pm

    haha I have actually had this problem! & since the answer’s already up, I will just voice my support for shiny new math problems. Trivia would be super fun too!

  9. Dan Sveaver (nee Toma) on February 3rd, 2010 2:09 pm

    I’m already looking forward to next Monday.

  10. Dan Sveaver (nee Toma) on February 3rd, 2010 2:16 pm

    What’s the probability that there’ll ever be a female gangster dubbed ‘Ma Thematics’ and, is it a *conditional* probability, considering that ‘Ma Barker’ existed.

  11. Ben Kusmin on February 3rd, 2010 3:34 pm

    If there’s no repeats there should be 210 possible schedules– the 5040 previously noted, divided by the (4×3x2×1) redundant versions of each lucky set of gentleman suitors.

  12. Bob V on February 5th, 2010 3:21 am

    Slots open: Thursday, Friday, Saturday1, Saturday2

    10 people could fill Thursday, but after that person is assigned, only 9 can fill Friday. 8 can then fill Saturday1 and 7 can fill Saturday2. This implies 10×9x8×7 possible schedules. On the other hand, if you consider dating Tim and then Jared on Saturday the same as dating Jared and then Tim, then divide the result by two. It would then be 10×9x8×7/2.

  13. jen on February 5th, 2010 4:08 am

    Welcome back, Bob! Yes, everybody pretty much nailed this one. So the next two weeks’ problems are harder!

    And “how many different social schedules,” I think, implies that Tim/Jared and Jared/Tim would be distinct combinations. After all, if you’re Tim or Jared, you probably want to be the nighttime guy — better chance of getting somewhere.

    Hmmn. Unless the daytime guy does get some, in which case being the nighttime guy could be kind of gross.

    It really depends. But they’re definitely different combinations.

Got something to say?