## Archive for March 6, 2013

### Math Jokes, Yo! Let It Snow…

If you live near northern Virginia, then you’re stuck inside on a snowy day. If you’re bored and need something to do, you could attempt to solve the snowplow problem from R. P. Agnew’s *Differential Equations* (McGraw-Hill, New York, 1942).

One day it started snowing at a heavy and steady rate. A snowplow started out at noon, going 2 miles the first hour and 1 mile the second hour. What time did it start snowing?

If you can’t find the solution easily (or if you think that the problem is unsolvable), don’t fret. This problem has befuddled students for 71 years.

If you’re not a masochist, though, then you may just like some math jokes for a snowy day.

Math Teacher: We’re going to have an exam tomorrow, rain or shine.

Student: Great! It’s snowing.What math do Snowy Owls study?

Owlgebra.

Or perhaps you enjoy jokes with more elaborate set-ups…

An elder in a Native American tribe is asked, “Will it be cold this winter?” Not wanting to appear ignorant, he tells them, “Yes, it will be cold this winter. I suggest you start collecting firewood to be prepared.” The tribe disperses immediately to start collecting wood. Meanwhile, the elder heads to a phone and calls the National Weather Service. He asks the person who answers, “Will it be cold this winter?”

The agent at NWS responds, “Yes, our early data indicates that it will be a cold winter.”

The elder returns to the tribe and tells them, “Keep collecting wood! A cold winter is on the way!” Just to be sure, the next day he calls NWS, and again he asks, “Will it be cold this winter?”

The agent responds, “Our data now suggests that the winter will be very cold.”

The elder informs the tribe, “It will be a very cold winter! More wood!”

Wanting to be certain that he is sharing correct information, he calls NWS again the following day. “Are you absolutely certain that it will be very cold this winter?”

“Yes!” says the NWS agent. “The Native Americans are collecting firewood at an unprecedented rate!”

### Teasing Out Some Math Jokes

Let’s do a quick warm-up before jumping into this post.

A boy leaves his house headed for school, walking at a rate of 4 miles per hour. Ten minutes later, his sister leaves the school headed for home, walking at a rate of 3 miles per hour. Assuming they travel the same route (just in opposite directions), which one will be nearer the school when they meet?

This problem is based on the first puzzle that appears in *Mathematical Teasers* by Julio A. Mira. As best I can tell, this book is out of print, and probably for good reason. Written in 1970, it contains no semblance of political correctness. For instance, the image below appears at the beginning of Chapter 1:

Hmm… a pigtailed coed in a skirt sitting on a desk, tickling the chin of a math professor? There is no doubt an editor in 2013 would prohibit such an image from appearing in a publication; quite honestly, I’m even surprised an editor allowed it 43 years ago.

My copy of this book was obtained when the National Council of Teachers of Mathematics cleaned out their staff library. Inside the front cover, an insert states that it was a review copy “sent with the compliments of Barnes and Noble, Inc.,” and a stamp on the insert reads:

**RECEIVED**

**MAY 26 1970**

**NCTM**

Despite its political incorrectness and outdated contexts, my five-year-old sons have been enjoying the puzzles in the book. But they aren’t just puzzles. Like the warm-up problem above, they are jokes, in the sense that the punch line (answer) is unexpected. The following are a few of my favorites.

- A man with $50 in a bank account withdraws $20, leaving $30. He then withdraws $15, leaving $15. Then $9, leaving $6. And finally $6, leaving $0. The sum of his withdrawals is 20 + 15 + 9 + 6 = $50, as expected, but the sum of the remainders is 30 + 15 + 6 + 0 = $51. Where did the extra dollar come from?
- If it takes 3 minutes to boil an egg, how long will take to boil a dozen eggs?
- How many cubic inches of dirt are in a hole that measures 1 ft. × 1 ft. × 1 ft.?
- A man purchased a pair of shoes that cost $25 and gave the shop owner a $100 bill. After the man left with the shoes and his change, the owner took the $100 bill to the bank, where he was told that it was counterfeit. What was the total loss to the owner?
- Every day, Johnson’s cat would climb 11 feet higher in a tree that is 63 feet tall. But every night, the cat would climb back down 7 feet. How many days would it take her to reach the top of the tree?

No answers will be posted. Y’all can attempt to reach consensus in the Comments section.