Saturday, April 22, 2017

Marking a Ruler


A 13-inch ruler only needs four markings on it so that it can be used to measure any whole number of inches from 1 to 13. At what positions should the four markings be? (Do not include the two ends, which are understood to be markings 0 and 13.) Click below to see the answer.



Saturday, April 15, 2017

Move One Digit


The following equation is incorrect. Can you make the equation balanced by moving only a single digit?

101 - 102 = 1

Click below to see the answer.



Saturday, April 8, 2017

What is the next number in the sequence?


Without Googling it, can you tell me the next number in the following sequence?

1
11
21
1211
111221
312211
13112221
1113213211

That should be enough to see the pattern, but this sequence goes on infinitely. Click below to see the answer.


Saturday, April 1, 2017

Beer Run


A man runs n laps around a circular track with a radius of t miles. He says he will drink s quarts of beer for every mile he runs. How many quarts will he drink? Click below for the answer.


Saturday, March 25, 2017

10-digit Number


Find a 10-digit number where the first digit is how many 0's there are in the number, the second digit is how many 1's in the number, the third digit is how many 2's, and so on, until the tenth digit which is how many 9's there are in the number.

Click below to see the answer.






Saturday, March 18, 2017

The Extra Dollar


Here is an old math puzzle that you can find many versions of online.

Two friends have a meal at a restaurant, and the bill is $25. The friends pay $15 each, which the waiter gives to the cashier. The cashier gives back $5 to the waiter. The friends tell the waiter to keeps $3 as a tip, so he hands back $1 to each of the two diners.

So, the friends paid $14 each for the meal, for a total of $28. The waiter kept $3, and that makes $31. Where did the extra dollar come from? Give yourself a moment to think about it before clicking below for the solution.


Saturday, March 11, 2017

Arranging Eights


Can you arrange eight 8's so that when added they will equal 1000? Click below to see the answer.