# Math Puzzle . ca - math and logic puzzles

#### Looking for brainteaser puzzles, mensa mind challenges, math puzzles and logic problems?

Welcome to MathPuzzle.ca the home of logic and math puzzles. Choose from hundreds of logic math puzzles
and brainteasers.
Start by
browsing the categories, they are divided into different logic type puzzles.
If you are unsure where to go, click on the random logic puzzle from the top menu.

## THE NINE SCHOOLBOYS.

(

Combination and Group Problems)

This is a new and interesting companion puzzle to the "Fifteen

Schoolgirls" (see solution of No. 269), and even in the simplest

possible form in which I present it there are unquestionable

difficulties. Nine schoolboys walk out in triplets on the six week days

so that no boy ever walks _side by side_ with any other boy more than

once. How would you arrange them?

If we represent them by the first nine letters of the alphabet, they

might be grouped on the first day as follows:--

A B C

D E F

G H I

Then A can never walk again side by side with B, or B with C, or D with

E, and so on. But A can, of course, walk side by side with C. It is here

not a question of being together in the same triplet, but of walking

side by side in a triplet. Under these conditions they can walk out on

six days; under the "Schoolgirls" conditions they can only walk on four

days.

Read Answer