Math Riddles

Math Riddle #361 (medium)

Question: If you have two twins, three triplets and four quadruplets; how many people do you have?

Math Riddle #347 (medium)

Question: You have two books. One of them is upside-down and the other is rotated so the top of the book is facing you.

What is the sum of the first page in each book?

Math Riddle #324 (medium)

Question: What temperature is twice as hot as 0 degrees Celsius?

Math Riddle #323 (medium)

Question: A swan is in the center of a circular lake but he cannot take flight from the water, only on land. On the parameter of the lake there is a hunting dog that desperately wants the swan but cannot swim. So the swan must make it to the land before taking off and must do so before the dog makes it to him. The dog is almost 4 times faster than the swan and always runs to the point around the lake closest to the swan.

How can the swan get out of the lake and take flight before the dog gets him?

Math Riddle #319 (medium)

Question: If a mountain climber climbed up a mountain one day from midnight to midnight the next day and does the same thing the following day when coming down the mountain, would there be a time at which he was at the same position on the mountain both day?