Riddle:
There is a creature which could double its size every day. So, if the creature is put in a tank then it will fill the tank in 10 days.
How many days would it take for the creature to fill 1/2 and 1/4 of the tank?
Answer: 9 days to fill 1/2 and 8 days to fill 1/4 of the tank. If the creature fills the tank in 10 days and it doubles every day, on the ninth day it would fill 1/2 the tank. Thus on the 8th day it will fill 1/4 of tank.
Riddle:
A 300 ft. train is traveling 300 ft. per minute must travel through a 300 ft. long tunnel. How long will it take the train to travel through the tunnel?
Answer: Two minutes. It takes the front of the train one minute and the rest of the train will take two minutes to clear the tunnel.
Riddle:
Why are 1999 ten pound notes worth more than 1993 ten pound notes?
Answer: Because there are more of them!
Riddle:
Two hours ago it was as long after one o'clock in the afternoon as it was before one o'clock in the morning. What time is it now?
Answer: It would be 9:00 pm. There are 12 hours between 1:00 pm and 1:00 am and half of that is six hours. Half-way between would be 7 o'clock. Two hours later it would be 9:00 o'clock.
Riddle:
Farmer Brown came to town with some watermelons. He sold half of them plus half a melon, and found that he had one whole melon left. How many melons did he take to town?
Answer: Three melons!
Riddle:
If place 1 cake of soap on a pan of a scale and 3/4 cake of soap and a 3/4-pound weight on the other, the pans balance.
How much does a cake of soap weigh?
Answer: Since 1/4 cake weighs 3/4 pound, and entire cake weighs 3 pounds.
Riddle:
You and your friend are trapped in a space prison on an alien planet. The alien warden decides to give you and your friend a chance at freedom. He states that your friend shall be allowed to temporarily leave your cell and try to escape through an electric gate guarded by a 3-number passcode. If your friend answers incorrectly or says anything but the final answer, your friend will be thrown back in the prison. A computer will then tell your friend 4 clues if requested. If this passcode is properly answered, you and your friend shall be freed. You are then blindfolded and your friend leaves. You hear your friend walk down one of the numbered hallways to the gate. Your friend asks for the first clue. A voice answers, "The numbers are in ascending order so that the number is greater than or equal to the number before it." Your friend asks for the second clue. The voice says, "The product of the 3 numbers is 36." Your friend asks for the third clue. The voice says, "The sum of the numbers is the number of the hallway you entered." Your friend pauses for a moment and thinks. Your friend then asks for the fourth and final clue. The voice says, "The largest number only appears once in the code." You hear a beep. You hear your cell door swing open. You are free! What was the code?
Answer: 2,2,9
Riddle:
A hundred stones are placed, in a straight line, a yard distant from each other. How many yards must a person walk, who undertakes to pick them up, and place them in a basket stationed one yard from the first stone?
Answer: In solving this question it is clear that to pick up the first stone and put it into the basket, the person must walk two yards, one in going for the stone and another in returning with it; that for the second stone he must walk four yards, and so on increasing by two as far as the hundredth, when he must walk two hundred yards, so that the sum total will be the product of 202 multiplied by 50, or 10,100 yards. If any one does not see why we multiply 202 by 50 in getting the answer, we refer him to his arithmetic.
Riddle:
What is the 4 digit number in which the first digit is one-fifth of the last, and the second and third digits are the last digit multiplied by 3?
Answer: 1155.
Riddle:
A half is a third of it. What is it?
Answer: 1 1/2.
Riddle:
A woman went into a bank to cash an insurance refund check. By mistake the teller gave her dollars for cents and cents for dollars. She put the money in her purse but accidentally dropped a nickel on the floor. When she got home, she found that she had exactly twice the amount of the check she had cashed. She didn't have any money in her wallet before going to the bank. What was the exact amount of that check?
Answer: The amount must have been $31.63. She received $63.31. After she dropped a nickel there would remain the sum of $63.26, which is twice the amount of the check.
Riddle:
How many pluses should we put between the digits of 987,654,321 to get a total of 99, and where?
Answer: (6) 9 + 8 + 7 + 6 + 5 + 43 + 21= 99
(7) 9 + 8 + 7 + 65 + 4 + 3 + 2 + 1= 99
Riddle:
When completed in 1889 the Eiffel Tower was something of a sensation. Designed by the French engineer Alexandre-Gustave Eiffel its height is 492 feet plus half its own height.
How high is the Eiffel tower?
Answer: 984 feet.
Riddle:
Walking home one day, you take a short cut along the train tracks. The tracks cross a narrow bridge over a deep gorge. At the point you are 3/8 of the way across the bridge, you hear the train whistle somewhere behind you. You charge across the bridge, and jump off the track as the train is about to run you down. As it happens, if you had gone the other way, you would have reached safety just before being run over as well. If you can run ten miles per hour, how fast is the train moving?
Answer: The train is moving at 40 miles per hour. Imagine that a friend is walking with you. When the train whistle blows, you head away from the train, he heads toward it. When he reaches safety, you will be 6/8 (or 3/4)of the way across the bridge, and the train will have just reached the bridge. For the train to cross 4/4 of the bridge in the time you cross the remaining 1/4, the train must be moving four times your speed.
Riddle:
Joe has ten coins totaling $1.19. From these coins, he cannot make exact change for a dollar, half-dollar, quarter, dime, or nickel.
What are the coins?
Answer: A half-dollar, a quarter, four dimes, and four pennies.
Riddle:
If 10 bags of jelly beans and 6 licorice sticks cost $1, and 10 licorice sticks and 6 jelly bean bags cost 92 cents.
How much does one licorice stick cost?
Answer: 5 cents while Jelly bean bags cost 7 cents.
Riddle:
Given two 2s, "plus" can be changed to "times" without changing the results: 2 + 2= 2 x 2.
The solution with three numbers is easy too: 1 + 2 + 3= 1 x 2 x 3.
What is the answer for 4 numbers and for 5 numbers?
Answer: Solution for 4 numbers:
1 + 1 + 2 + 4= 1 x 1 x 2 x 4.
Solution for 5 numbers:
1 + 1 + 1 + 2 + 5= 1 x 1 x 1 x 2 x 4
1 + 1 + 1 + 3 + 3= 1 x 1 x 1 x 2 x 4
1 + 1 +2 + 2 + 2= 1 x 1 x 2 x 2 x 2
Riddle:
My only timepiece is a wall clock. One day I forgot to wind it and it stopped. I went to visit a friend whos watch is always correct, stayed awhile, and then went home. There I made a simple calculation and set the clock right.
How did I do this even though I had no watch on me to tell how long it took me to return from my friend's house?
Answer: Before I left, I wound the wall clock. When I returned, the change in time equaled how long it took to go to my friends house and return, plus the time I spent there. But I knew the latter because I looked at my friends watch when I arrived and left.
Subtracting the time of the visit from the time I was absent from my house, and dividing by 2, I obtained the time it took me to return home. I added this time to what my friend watch showed when I left, and set the sum on my wall clock.
Riddle:
A girl is twice as old as her brother and half as old as her father. In 50 years, her brother will be half as old as his father. How old is the daughter now?
Answer: 50 years old.
Riddle:
Twelve flags stand equidistant along the track at the stadium. The runners start at the first flag. A runner reaches the eighth flag 8 seconds after he starts. If he runs at an even speed, how many seconds does he need altogether to reach the twelfth flag?
Answer: Not 12 seconds. There are 7 segments from the first flag tot the eighth, and 11 from the first to the twelfth. He runs each segment in 8/7 seconds; therefore, 11 segments take 88/7= 12 4/7 seconds.
