Feed on
Posts
Comments

Problem Ten: Mulling Over Multiplication

Sep 26th, 2006 by Percy

What number is it that, when multiplied by 18, 27, 36, 45, 54, 63, 72, 81, or 99, gives a product in which the first and last figures are the same as those in the multiplier, but which when multiplied by 90 gives a product in which the last figures are the same as those in the multiplier?

Source: 536 Puzzles & Curious Problems by Dudeney

Update: Solutions are posted

Posted in Mathematical | 8 Comments

8 Responses to “Problem Ten: Mulling Over Multiplication”

  1. on 26 Sep 2006 at 6:21 pm   Percy

    And no, it’s not 1. :D

  2. on 26 Sep 2006 at 10:28 pm   tony

    I found it!
    Show ▼

  3. on 27 Sep 2006 at 6:27 pm   tracey

    How do you do the “Show” thing?

  4. on 27 Sep 2006 at 7:43 pm   tony

    Show ▼

    obviously without the spaces

  5. on 27 Sep 2006 at 7:44 pm   tony

    hmm that didn’t show much…
    Here we go again:

    stuff except you don’t type the one

  6. on 27 Sep 2006 at 7:45 pm   tony

    that didn’t show either! WTF

    \Show ▼

  7. on 27 Sep 2006 at 7:46 pm   tony

    AHHH!!!

    ok just use “spoiler” tags like html tags…

  8. on 30 Sep 2006 at 3:12 pm   tony

    <spoiler> stuff </spoiler>

Trackback URI | Comments RSS

Leave a Reply