Christian Huygens was a Dutch mathematician, physicist and astronomer, born in The Hague, The Netherlands, on April 14, 1629. He was the second of four children of the poet and diplomat Constantijn Huygens (1596-1687). He was a man of wide culture who also devoted himself to the sciences. From his father, Huygens received his first instruction in mathematics and mechanics at the age of thirteen, and from early on aroused interest and skill in both.
The next word Difficulty level: The following word sequence follows a certain rule: T-shirt, acetone, monkey, pineapple, magic What is the next word in the sequence? a) horse b) olive oil c) mayonnaise d) publication e) basketball Challenge 139 Olive in the Cup Challenge Index Next >> Challenge 141 Adroaldson's Wallet
Adroaldson's Wallet Level of difficulty: Adroaldson lost his wallet and went to the police station to report the incident. Arriving there, a police officer told him that a wallet was found and asked Adroaldson to report the contents of his wallet. Adroaldson said he had $ 63.00 in six notes and none of them was $ 1.00.
The Fly and the Cyclist Difficulty Level: Two cyclists, in opposite directions, approached on a straight road, pedaling at 20km / h. When 40km away, a fly lands on one of the bikes, then flies to another. Then the fly keeps coming and going between the two bikes, flying at 30km / h, until the cyclists meet.
A special symbol Difficulty level: The symbol represents a special operation with numbers. Here are some examples: 2 4 = 10 3 8 = 27 4 27 = 112 5 1 = 10 How much is 4 (8 7) worth? Challenge 157 Multiple of 9 Challenge Index Next >> Challenge 159 Little John Waiting for Bus
The Flood and the Jealous Husbands Difficulty Level: After a flood, three couples were surrounded by water and were forced to flee their hotel on a boat that could hold no more than three people at a time. Each husband was so jealous that he would not allow his wife to stay in the boat, or anywhere, with any other man (or men) unless he himself was present.
Handshaking Difficulty Level: At the end of a meeting, everyone in attendance shook hands. Edigleidson, who was present, said there were 66 handshakes. How many people attended this meeting? Challenge 161 As many challenges as possible Challenge Index Next >> Challenge 163 The Cat, the Coffee, and the Cake
The Beggar and the Cigarettes Difficulty Level: Math Only Warns: Smoking is Harmful to Health! A beggar can make one cigarette every 6 cigarette butts he finds. After a full day roaming the streets and checking public ashtrays, the beggar found 72 cigarette butts. How many cigarettes can he smoke?
Throwing Dice Difficulty Level: You have two normal six-sided dice, numbered 1 through 6. When you roll them, the total was 5. You will be the winner if you make another 5 before making a 7, otherwise you loses. If it is any other combination before a 5 or a 7, you roll the dice again.
Diophantus' Puzzle Level of Difficulty: History has kept little data about Diophantus. All that is known about him is found in the following epigram on his grave and written in the form of a mathematical riddle: Walker! Here are buried the remains of Diophantus. And the numbers can show (miracle!
All without debt Difficulty Level: A traveler arrives in a country town and enters a small hotel. At the reception, she delivers $ 100.00 and asks to see a room. While the traveler inspects the rooms, the hotel manager runs off with the $ 100 bill and goes to the butcher's shop to pay his debt.
Ice Cream Promotion Difficulty Level: One summer, an ice cream factory held a promotion that included exchanging ten ice cream sticks for a stick ice cream. In this promotion, an ice cream stick corresponds to what fraction of the price of an ice cream? Challenge 142 Discover the King's Name Challenge Index Next >> Challenge 144 The Five Apples
Spinning the Coin Difficulty Level: There is an old challenge in which we have one coin standing and one spinning around it. It turned out that the coin (spinning) can make two full turns around the other, which is standing still. Now try to find out: how many full spins will one coin make around three fixed coins in a row?