Try to read the word in the first figure, using the key (see the second figure).
Six chess players participated in a tournament. Each two participants of the tournament played one game against each other. How many games were played? How many games did each participant play? How many points did the chess players collect all together?
Try to make a square from a set of rods:
6 rods of length 1 cm, 3 rods of length 2 cm each, 6 rods of length 3 cm and 5 rods of length 4 cm. You are not able to break the rods or place them on top of one another.
Write a number instead of the space (in letters, not numbers!) to get a true sentence:
THIS SENTENCE HAS ... LETTERS
(Note that the dash does not count as a letter, i.e. the word twenty-two is made up of 9 letters).
A schoolboy told his friend Bob:
“We have thirty-five people in the class. And imagine, each of them is friends with exactly eleven classmates...”
“It cannot be,” Bob, the winner of the mathematical Olympiad, answered immediately. Why did he decide this?
Once Alice was in one of two countries – A or Z. She knows that all of the residents of country A always tell the truth, and all the inhabitants of country Z always lie. Moreover, they often go to visit each other. Can Alice, after asking a single question to the first person that she meets, find out which country she is in?
Cowboy Joe was sentenced to death in an electric chair. He knows that out of two electric chairs standing in a special cell, one is defective. In addition, Joe knows that if he sits on this faulty chair, the penalty will not be repeated and he will be pardoned. He also knows that the guard guarding the chairs on every other day tells the truth to every question and on the alternate days he answers incorrectly to every question. The sentenced person is allowed to ask the guard exactly one question, after which it is necessary to choose which electric chair to sit on. What question can Joe ask the guard to find out for sure which chair is faulty?
In an ordinary set of dominoes, there are 28 tiles. How many tiles would a set of dominoes contain if the values indicated on the tiles did not range from 0 to 6, but from 0 to 12?
What are the eight coins you need to take, so that you can use them to pay without change any amount from 1 pence up to 1 pound?
(In circulation at the time, there were coins of 1, 3, 5, 10, 20 and 50 pence).
The director of a power plant, considering the list of phone numbers and the names of his employees, noticed a certain relationship between names and phone numbers. Here are some names and phone numbers from the list:
Achinskiy 9125
Butenko 7215
Dapin 5414
Galick 6711
Martyanof 9136
Romidze 7185
What is the phone number of an employee named Ognef?