Riddle: A woman is walking down a street night at a constant pace. As she passes the street light, she notices that her shadow becomes longer. Does the top of her shadow move faster, slower or the same when the shadow is longer as when it is shorter?
Answer: This point maintains a constant speed, independent of the lenght of the shadow.
Riddle: An item is made from lead blanks in a lathe shop. Each blank suffices for 1 item. Lead shavings accumulated for making 6 items can be melted and made into a blank. How many items can be made from 36 blanks?
Answer: From 36 blanks there are 36 items made. The lead shavings are enough to make 6 blanks. Which make 6 more items. But don't stop here. The new shavings are good for 1 more item. Total: 43.
Riddle: Jenna wrote all the numbers from 300 to 400 on a piece of paper. How many times did she write the digit 3?
Answer: Jenna wrote it 120 times.
Math Riddles
Riddle: What is 1/2 of 1/4 of 2/9 of 3/7 of 84?
Answer: The answer is 1. 3/7 of 84 = 36 2/9 of 36 = 8 1/4 of 8 = 2 1/2 of 2 = 1
Riddle: Jack has 8 bricks 7 of them weights the same amount and one is slightly heavier. Using a balance scale, how can Jack find the heavier brick in two weighings?
Answer: First he split them in to piles of 3, 3, and 2 bricks. Then he weighs both groups of 3 with each other. If they balance he knows the brick is one of the 2 unweighed bricks and he can weigh them to find the heaver one. If the the stacks of 3 bricks do not balance, he will weigh 2 of the 3 bricks. If they balance he will know the brick left unweighed is heavier, or if they do not balance, he will find the heavier one.
Math Riddles
Riddle: Two travellers spend from 12 o'clock to 6 o'clock walking along a level road, up a hill and back again. Their pace is 4 mph on the level, 3 mph uphill, and 6 mph downhill. How far do they walk and at what time do they reach the top of the hill?
Answer: 24 miles half past three.
Riddle: Robert and David were preparing to have a water balloon fight. "No Fair" cried Robert, "You have 3 times as many as I do!" David said "Fine!" and gave Robert 10 more balloons. "Still not fair!" argued Robert, "You still have twice as many as I do." How many more balloons must David give Robert for them to have the same number?
Answer: David must give Robert another 20 water balloons, giving them each 60. Robert started with 30 water balloons and David with 90.
Math Riddles
Riddle: A car's odometer shows 72927 miles, a palindromic number. What are the minimum miles you would need to travel to form another?
Answer: 110 miles. (73037)
Riddle: What number, when added separately, to 100 and 164 can make each a perfect square?
Answer: The answer is 125. 125+100=225 and 125+164=289.  The square root of 225 is 15 and the square root of 289 is 17.
Riddle: A man told his son that he would give him $1000 if he could accomplish the following task. The father gave his son ten envelopes and a thousand dollars, all in one dollar bills. He told his son, "Place the money in the envelopes in such a manner that no matter what number of dollars I ask for, you can give me one or more of the envelopes, containing the exact amount I asked for without having to open any of the envelopes. If you can do this, you will keep the $1000." When the father asked for a sum of money, the son was able to give him envelopes containing the exact amount of money asked for. How did the son distribute the money among the ten envelopes?
Answer: The contents or the ten envelopes (in dollar bills) should be as follows: $1, 2, 4, 8, 16, 32, 64, 128, 256, 489. The first nine numbers are in geometrical progression, and their sum, deducted from 1,000, gives the contents of the tenth envelope.