In the gymnasium, all students know at least one of the ancient languages – Greek or Latin, some – both languages. 85% of all children know the Greek language and 75% know Latin. How many students know both languages?
Before the start of the Olympics, the price of hockey pucks went up by 10%, and after the end of the Olympics they fell by 10%.
When were the pucks more expensive – before the price rise or after the fall?
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?
Is it possible to fill a \(5 \times 5\) table with numbers so that the sum of the numbers in each row is positive and the sum of the numbers in each column is negative?
The distance between Athos and Aramis, galloping along one road, is 20 leagues. In an hour Athos covers 4 leagues, and Aramis – 5 leagues.
What will the distance between them be in an hour?
Pinocchio and Pierrot were racing. Pierrot ran the entire race at the same speed, and Pinocchio ran half the way two times faster than Pierrot, and the second half twice as slow as Pierrot. Who won the race?
Try to decipher this excerpt from the book “Alice Through the Looking Glass”:
“Zkhq L xvh d zrug,” Kxpswb Gxpswb vdlg, lq udwkhu d vfruqixo wrqh, “lw phdqv mxvw zkdw L fkrrvh lw wr phdq – qhlwkhu pruh qru ohvv”.
The text is encrypted using the Caesar Cipher technique where each letter is replaced with a different letter a fixed number of places down in the alphabet. Note that the capital letters have not been removed from the encryption.
Find out the principles by which the numbers are depicted in the tables (shown in the figures below) and insert the missing number into the first table, and remove the extra number from the second table.
Everyone believed that the Dragon was one-eyed, two-eared, three-legged, four-nosed and five-headed. In fact, only four of these definitions form a certain pattern, and one is redundant. Which characteristic is unnecessary?
Jemima always tells the truth, but when she was asked the same question twice, she gave different answers. What kind of question could this be?