Math Riddles

 

Question: When is... 5>0, 0>2 and 2>5? Hint: Hands


3 coins (medium)

Question: You have three coins. One always comes up heads, one always comes up tails, and one is just a regular coin (has equal change of heads or tails). If you pick one of the coins randomly and flip it twice and get heads twice, what is the chance of flipping heads again?

The Tide (medium)

By Fred

Question: At low tide 14 rungs of a ship are above the water, the rungs are 15 centimeters apart. each 15 mins the water rises 15 centimeters. after 2 hours and 30 mins how many rungs are above the water?

Question: In 1940, a correspondent proposed the following question:

A man's age at death was one twenty-ninth of the year of his birth. How old was he in 1900?

Question: 1. A bat and a ball cast $1.10 cents in total. The bat costs one dollar more than the ball. How much does the ball cost? 2. If five machines made five gadgets in five minutes, how much time would it take for 100 machines to make 100 gadgets? 3. The was a lake, it was full with lily pads, each day the lily pads doubled in size, it took 48 days for the lily pads to cover all of the lake how long would it take for the lily pads to cover half of the lake?