Is it always the case that in any 25 GBP banknotes – that is £5, £10, £20, and £50 notes – there will always be 7 banknotes of the same denomination?
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?
Fred and George are twin brothers. One of them always tells the truth, and the other always lies. You can ask only one question to one of the brothers, to which he will answer “yes” or “no”. Try to find out the name of each of the twins.
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?
It is known that “copper” coins that are worth 1, 2, 3, 5 pence weigh 1, 2, 3, 5 g respectively. Among the four “copper” coins (one for each denomination), there is one defective coin, differing in weight from the normal ones. How can the defective coin be determined using scales without weights?
How can we divide 24 kg of nails into two parts of 9 kg and 15 kg with the help of scales without weights?
Harry, Jack and Fred were seated so that Harry could see Jack and Fred, Jack could only see Fred, and Fred could not see anyone. Then, from a bag which contained two white caps and three black caps (the contents of the bag were known to the boys), they took out and each put on a cap of an unknown color, and the other two hats remained in the sack. Harry said that he could not determine the color of his hat. Jack heard Harry’s statement and said that he did not have enough information to determine the color of his hat. Could Fred on the basis of these answers determine the color of his cap?
Five first-graders stood in line and held 37 flags. Everyone to the right of Harley has 14 flags, to the right of Dennis – 32 flags, to the right of Vera – 20 flags and to the right of Maxim – 8 flags. How many flags does Sasha have?