More Trick Problems
New additions to my trick problems collection:
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It takes 12 minutes to saw a log into 3 parts. How much time will it take to saw it into 4 parts?
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The Davidsons have five sons. Each son has one sister. How many children are there in the family?
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A caterpillar wants to see the world and decides to climb a 12-meter pole. It starts every morning and climbs 4 meters in half a day. Then it falls asleep for the second half of the day during which it slips 3 meters down. How much time will it take the caterpillar to reach the top?
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Mike:
Ah tricky! I remember the first one from a problem solving book.
28 April 2010, 9:50 pmIlya:
May I suggest another problem to your collection:
29 April 2010, 2:07 amJohn and David were playing chess for two hours. How much time was John playing?
James:
I can think of two plausible “trick” answers to the log problem. One answer is 2/3 as big as the other. I wonder which one is intended….
29 April 2010, 7:05 amSergei:
I could easily see the first being anything from 12-18 minutes.
29 April 2010, 9:20 amcolorblind:
Allow me to present the Davidsons:
The patriarch Antone Davidson, 109, and his partner Antonia, 108. (A long-lasting marriage to admire, no?)
Arthur’s children Bobby, 94 and Bobbie, 93.
Bobby’s twins Chris, 77, and Kris, 77. (Twins!)
Chris’s kids Daniel, 59, and Danielle, 43.
Dan’s kids Elvis, 40 and Elvira, 40. (Not twins!)
And last but not least, Elvis’s kids, Francis and Frances, both recently turned 18.
There’s a rumor both Frances and Elvira are pregnant, but we shall see…the family misses hearing the pitter-patter of children’s feet.
Now I hear the Davidsons have distant cousins over in the old country with lots of kids. In fact, their cousin Jordan has 6 kids: Pat, Robin, Lou, Jamie, Jessie, and Sasha. Evidently, having 5 strapping sons and an adorable daughter makes him the pride of that side of the family.
So, to summarize, there could be 10 kids, there could be 0, and if we’re imaginative we could make any integer in between 0 and 10 a solution.
8 May 2010, 9:57 amChrist Schlacta:
if a log is cut into three pieces like so: [ |—–] such that there’s an end piece that takes three minutes to cut and a long cut that takes 9 minutes to cut, we can surmise that the second log to cut might be smaller or larger than the first log and therefore could take any amount of time to cut.
8 January 2011, 7:02 pmMonkey:
The answer to the first one is obviously 16 minutes, it isn’t even a trick question
28 May 2013, 6:22 pmTanya Khovanova:
Monkey,
You need to make 2 cuts to divide something into three parts. So each cut is 6 minutes.
28 May 2013, 6:57 pm