Penny, Cork and A Bottle

Given a corked bottle with only a penny inside, how can you remove the penny without pulling out the cork, breaking the bottle and leaving the cork intact?

Push the cork into the bottle, then shake the penny out.

Posted in Brain Teasers

Horse Fence

Farmer Finnegan needs to build a fence to keep his horses on his property. He only has a little over 1.5 miles of fence materials, but there’s also a mile-long straight river running through his property. What shape should he use for the fenced in area to give his horses the most space possible?

Our dear friend Finnegan should build a half-circle fence with the river as the diameter, giving the horses about 0.4 square miles to frolic and play in.

Area of semi-circle = πr2 / 2 = π × .5 miles2 / 2 = 0.3927

Posted in Brain Teasers

lainws

What does this mean?

lainws

In-laws. The word in is found inside the word laws.

Posted in Brain Teasers
Tagged with

Four Legs in the Morning

It walks on four legs in the morning, two legs at noon and three legs in the evening. What is it?

Man (or woman). A baby crawls on all fours, then walks on two legs as an adult and uses two legs and a cane when they’re old.

Posted in Riddles

Word Party

You watch a group of words going to a party. A word either enters through one of two doors or is turned away by the guards. ‘HIM’ goes through door number one and ‘BUG’ goes through door number two. ‘HER’ is turned away. ‘MINT’ and ‘WEAVE’ go in through door one, ‘DOOR’ and ‘CORD’ take door two and ‘THIS’ and ‘That’ aren’t allowed in.

What determines whether a word can enter and which door they must use?

Door number one is for words composed entirely of capital letters written using only straight lines, such as A, E, F, H, and I. The entire set of letters allowed through door number one are AEFHIKLMNTVWXYZ. Door number two, as might be expected, is for words with capital letters that have a curve, including BCDGJOPQRSU. Any words composed of both straight and curved letters (or lowercase letters) are not allowed in. The word ‘THAT’ would have been sent through door number one, if the letters had been capitalized.

Posted in Brain Teasers

Sum of 22

Fill in numbers such that the sum of each 3-character row is 22 while the sum of all five numbers is 30.

a
b c d
e

The problem works out to a set of three equations:
b + c + d = 22
a + c + e = 22
a + b + c + d + e = 30

Solving for c = 14, leaving d = 8 – b and e = 8 – a. In other words, c must be 14, but the other two numbers just have to add up to 8. The requirement that they be unique rules out 4 + 4, so you’re left to choose from the following combations for b + d and a + e:
0 + 8
1 + 7
2 + 6
3 + 5

Posted in Brain Teasers

Mislabeled Boxes of Marbles

Three closed boxes have either white marbles, black marbles or both, and they are labeled white, black and both. However, you’re told that each of the labels are wrong. You may reach into one of the boxes and pull out only one marble. Which box should you remove a marble from to determine the contents of all three boxes?

The one labeled both. Since you know it’s labeled incorrectly, it must have all black marbles or all white marbles. After you determine what it contains, you can identify the other two boxes by the process of elimination.

Posted in Brain Teasers

A Silent Murder Witness

Emily witnessed a murder in early January but didn’t call the police. Why?

It was a murder of crows.

Posted in Brain Teasers

The Pattern of Numbers

These series follow a pattern.
2 4 8
1 17 476
65 20987 3571890

This series does not follow the pattern
18 79 45

What is the pattern?

The numbers must be in ascending order. This can be a fun one to have people work out in person, as they test out three-number series and you can tell them whether or not they satisfy the pattern.

Thanks to Patrick for sending this in and thanks to this video from Veritasium for inspiring Patrick.

Posted in Brain Teasers

Downward Grows the Root

Downward grows the root.
Outward grows the skin.
Upward grows the shoot.
What way blows the wind?

Wayward.

By Sef Daystrom

Posted in Riddles