Monthly Archive - October 2013brain teasers, puzzles, riddles, mathematical problems, mastermind, cinemania... These are the tasks listed 1 to 10.
On which finger will she stop?A little girl counts from 1 to 1000 using the fingers of her left hand as follows. She starts by calling her thumb 1, the first finger 2, middle finger 3, ring finger 4, and little finger 5. Then she reverses direction, calling the ring finger 6, middle finger 7, the first finger 8, and her thumb 9, after which she calls her first finger 10, and so on. If she continues to count in this manner, on which finger will she stop?
Calculate the number 100NUMBERMANIA: Calculate the number 100 using numbers [1, 1, 4, 2, 20, 75] and basic arithmetic operations (+, -, *, /). Each of the numbers can be used only once.
A linguistics professor was lecturing to his class one day. "In English," he said, "a double negative forms a positive. In some languages though, such as Russian, a double negative is still a negative."
"However," he pointed out, "there is no language wherein a double positive can form a negative."
A voice from the back of the room piped up, "Yeah. Right."