Posts tagged ‘trivia’

GRiN and Solve It

My boys have been asking to do Math Trivia before bedtime each night, and one of my favorite sites, GRiN: Good Riddles Now, has provided a treasure trove of fun puzzles that they can solve.

Here’s one of them.

There are 100 coins on the floor in a dark room: 90 coins show heads, the other 10 show tails. If you’re not allowed to turn on any lights, how can you divide the coins into two piles so that each pile contains the same number of coins showing tails?

GRiN was started by Justin Zablocki, a math major cum computer scientist who enjoys logic and puzzles. He created GRiN as a way to practice his web development skills and to “improve upon an underdeveloped entertainment category.” (Hear, hear!)

His favorite math joke?

Why does no one talk to π?
He’s irrational and goes on forever.

His favorite riddle?

A murderer is condemned to death. He has to choose between three rooms. The first is ablaze with raging fires, the second is full of assassins with loaded guns, and the third contains lions who haven’t eaten in three years. Which room is safest for him?

Keeping with today’s theme, here’s a math riddle quiz for ya. Enjoy.

  1. How is the moon like a dollar?
  2. A plane with 56 passengers crashes on the border between Canada and the United States. Where do they bury the survivors?
  3. When spelled out, what is the first positive integer that contains the letter a?
  4. In a race of 548 runners, you overtake the last runner. What place are you now in?
  5. The first term of a sequence is a1 = 13. Every term thereafter satisfies a1 ∙ a2 ∙∙∙ ak = k! for k > 1. What is the 31st term of this sequence?
  6. There are four cookies in the cookie jar. You take three of them. How many do you have?
  7. If you remove the first letter, the last letter, and all the letters in between, what do you have left?
  8. What is the next number in the sequence 1, 4, 5, 6, 7, 9, 11, …?
  9. What is the product of all the digits on a telephone dialpad?
  10. If you have 6 apples in one hand and 7 oranges in the other, what do you have?
  11. What has a face and two hands but no arms or legs?
  12. What occurs once in a minute, twice in a moment, but never in a thousand years?
  13. A man has four daughters, and each daughter has a brother. How many children does the man have?


  1. Both have four quarters.
  2. You don’t bury survivors.
  3. One thousand.
  4. Trick question. It’s not possible to overtake the last runner, because you’d have to be behind him, in which case you’d be the last runner.
  5. 31.
  6. Three.
  7. The mailman.
  8. 100. The pattern of numbers are the positive integers that do not have a t in them when spelled out.
  9. 0.
  10. Big hands.
  11. A clock.
  12. The letter m.
  13. 5. One son is a brother to each of the daughters.

November 7, 2014 at 7:55 pm 4 comments

National Trivia Day

Here’s an interesting piece of trivia — January 4 is National Trivia Day! There are a number of ways to celebrate:

  1. Call someone and relay a useless piece of information. I plan to call my friends and tell them, “Did you know that in right triangle ABC with points D, E, and F lying on lines BC, CA, and AB, respectively, that AD, BE and CF are concurrent if and only if AF/FB × BD/DC × CE/EA = 1? Have a great day.” [click]
  2. Play Trivial Pursuit, Wits & Wagers, or some other trivia board game.
  3. Stand on the corner of a busy street and shout trivial math facts like a town crier. I recommend correcting misconceptions: “Hear ye, hear ye! Be it known that Henry the Eighth did not invent fractions; that the Pythagorean theorem was not discovered by Pythagoras; that, for the milionth time, (a + b)2 ≠ a2 + b2; and, that a junk yard is not 3 feet of trash.”
  4. Find a time machine and use it to locate the people who thought to put slotted holes in pancake flippers and ask them what the @#$% they were thinking. Then search for the designers of bell-bottomed pants, plastic wrap that sticks to nothing but itself, and doors for which it is not intuitively obvious whether you should push or pull.
  5. Take the math purity test.
  6. Take a roll of pennies and several $20 bills with you to the local grocery store. Put them in your left pocket. Then ask every adult patron in the store, “What do you call the line that separates the numerator and denominator of a fraction?” Each time someone answers, “Fraction bar,” which is correct yet unsophisticated, move a penny from your left pocket to your right pocket. Each time someone says, “I don’t know,” move a penny from your right pocket back to your left pocket. Each time someone answers, “Vinculum,” which is the most correct answer, move a $20 bill to your right pocket. And if someone responds with the question, “What’s a fraction?” leave the store immediately, concede that public education is in need of all the help you can offer, and give the money from both pockets to a local school. After surveying every patron in the store, go buy yourself a treat with the money remaining in your right pocket. (At best, I suspect you’ll have enough for a lollipop or perhaps a piece of chewing gum.)

January 4, 2011 at 7:52 pm Leave a comment

About MJ4MF

The Math Jokes 4 Mathy Folks blog is an online extension to the book Math Jokes 4 Mathy Folks. The blog contains jokes submitted by readers, new jokes discovered by the author, details about speaking appearances and workshops, and other random bits of information that might be interesting to the strange folks who like math jokes.

MJ4MF (offline version)

Math Jokes 4 Mathy Folks is available from Amazon, Borders, Barnes & Noble, NCTM, Robert D. Reed Publishers, and other purveyors of exceptional literature.

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