Five Brothers

Richard's father has five sons; four are named Alan, Elan, Ilan, and Olan. What is the name of the fifth son?

O T T F F S S E

A reader wonders what the next letter in the following series should be:

O T T F F S S E ...

Can I count on you to help them out?

Five Men and Two Bridges

In the puzzle Crossing the Bridge, we met four people who needed to cross a bridge at night. In this puzzle there are five people who have to cross two sequential bridges at night. Like in the earlier puzzle, there are some hindrances:

The bridges can only support two people crossing at a time.

Each person has a different speed in which they can cross: 10 minutes, 7 minutes, 5 minutes, 2 minutes, and 1 minute.

They only have two flashlights to share between them. A pair of people can share one flashlight, which means there can be one pair of people on each of the two bridges at the same time.

If the short time it takes to get from the first bridge to the second can be ignored, what is the shortest amount of time it will take for all five people to cross both bridges?

Crossing the Bridge

Four men must cross an old bridge that spans a raging river. I'm not sure, but it might be the same river that the Victorian couples and the man with the tiger and goat needed to cross as well. The bridge is old and rickety and can only support two men crossing at once. To make matters even worse, it is pitch black and they have only one flashlight to share between them, which means that after two men have crossed one must return with the flashlight. Each of the men has differing abilities and some take more time to cross than the others. The times it takes for each man to cross are: 1 minute, 2 minutes, 5 minutes, and 10 minutes. When crossing in pairs, they can only cross as fast as the slowest man can go.

Can you find a way for all four men to cross in 17 minutes or less?

The Magic Keyring

Engrave numbers on 5 keys on a circular keyring so that the numbers on adjacent groups of keys sum to any value between 1 and 21 inclusively.

For example, 1,1,3,6,6 can sum up to any number between 1 and 17 (1=1, 1+1=2, 3=3, 3+1=4, 3+1+1=5, 6=6, 6+1=7, 6+1+1=8, 6+3=9, 6+3+1=10, etc).

The Red Herring

A 'Red Herring' is a plot device used in literature to distract the reader away from the main event of the story by focusing on a minor event or describing characters in ways that go against our sense of the way those character should be. In cryptography, a red herring is a second hidden message that is intended to be discovered more easily so that the real message remains hidden to anyone who might intercept the transmission and break the red herring code. Only the intended receiver would know the key to unlocking the real message.

The cryptogram below, with two hidden messages, is a prime example of a red herring. One message is fairly easy to decipher, especially if you were able to decode an earlier puzzle that appeared here: http://puzzlepage.blogspot.com/2008/01/find-hidden-message.html. The second message, the one that's the real message, is hidden using a different code that has been made to fit in the same grouping of numbers. This is an extremely difficult cryptogram to solve, so feel free to ask for hints in the comment section.


21941648698194164869819416486981
54961847952716486981947648697358
39114467658829115524463869851941
76487962174268859915413638294575
51947682873991174467835921746687
82992113426384971634855658399727
12432613829431624856389791172446
83953124636885997711344766849911
44758746436849618496184961849618
49361849618898184961849618496184
69819416486981941648698194164869
81961635248698194164869819416486
89915214466889912144668899114466
88279911446688995114466889911446
75879618496188921246648691144666
89921347658591134764869871924164
86921354456289291314419885991234
61839518465768533281559123134362
84931546687899361547678297124312
44951746678897194362778135951543
64856618399613949711429889811444
48896919466819961882828694114914
49981941698618994964219181649644


Good luck!

It's Hip to be Square

Arrange two of each of the digits 0 through 9 to form a 20 digit number. The number may not begin with 0. Then score the number as follows:

For every two consecutive digits that form a perfect square, score two points. For every three consecutive digits that that form a perfect square, score three points. A four digit square scores four points, and so on.

For example, if your number was 58738219024719503664, you would get two points for 49, two points for 36, two points for 64, and six points for 219024 for a total of 12 points. You may not count 036 as a three digit square.

What is the maximum number you can score?

The Victorian Boat Ride

There are three couples trekking across the countryside when they come to a river that is too deep and to wide for them to swim across. On the near shore is a boat which they can use to cross the river, but there are some complications that keep them from crossing together.

First of all, the boat is only large enough to carry two people at a time.

Secondly, the couples, being Victorian, are very mindful of proper etiquette and it would be completely improper for a woman to be in the company of another man unless her husband is present.

How can all six people cross the river with a maximum of 2 people crossing at any one time and no woman being in the presence of a man unless her husband is also present?

M & M

What comes next in the following sequence?

1212210202001, 224000000, 11333311, 623351, 290221, ...?

1 to 12 in a Cross

Write the numbers 1 through 12 in the squares below so that the two columns, the two rows, and the five squares that can be formed with four numbers in each have a total sum of 26.


Can you find the solution where no two consecutive numbers are next to each other horizontally, vertically, or diagonally?

Seven Pairs of Numbers

If two 1s, two 2s and two 3s are arranged like this:

2 3 1 2 1 3

then the two 1s enclose 1 other digit, the two 2s enclose 2 other digits, and the two 3s enclose 3 other digits.


Can you find a similar arrangement using the seven pairs 1, 1, 2, 2,...7, 7?

A E F H I K L M N

A visitor to this site asks:

"I have the first part to a series of letters but I don't know how to finish the sequence."

The sequence starts out as:

A E F H I K L M N

Can you find the last 6 entries in this series for our fellow reader?

A Sequence of Numbers

Professor Egghead showed one of his graduate students the following 3 numbers:

1 5 9

and asked him "Do you know what the next one is?"

The student replied, "With only three numbers it would be very difficult to figure out the sequence but it appears to be an arithmetic series with each number being 4 more than the previous one."

Professor Egghead smiled knowingly and said "Some say the fourth number of the sequence is 3 times the second number, others claim it is the sum of the first three. Do you know the fifth, which is also the last number of the series?"

The student wrote four numbers on a piece of paper and was totally baffled as to what the last number could be. "Why would you think I should know this?" he asked.

Professor Egghead answered "Because you like to read."