Outrunning A Train 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?
Hint:
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. Did you answer this riddle correctly?
YES NO
YES NO
Three Rivers Riddle
There are three rivers and after each river lies a grave. A man wants to leave the same number of flowers at each grave and be left with none at the end. However, each time he passes through a river, the number of flowers he has doubles. How many flowers does he have to start with so that he is left with none at the end? And how many does he leave at each grave?
Hint:
This problem has an infinite number of solutions modeled by the equation 8a=7n, where a is the amount of flowers the man starts with and n is the number of flowers he leaves at each grave. The simplest and possibly trivial solution would be to start with 0 flowers and leave 0 flowers at each grave. A more significant solution would be to start with 7 flowers and leave 8 at each grave. Any positive integer multiple of this solution also satisfies the conditions. For example, the man starts with 14 flowers and leaves 16 at each grave; so, 14 doubles to 28, and 28-16= 12; 12 doubles to 24, and 24-16= 8; 8 doubles to 16, and 16-16= 0. The result is the same if the man starts with 21 flowers and leaves 24 flowers at each grave, or starts with 28 and leaves 32. Did you answer this riddle correctly?
YES NO
YES NO
A List Of Names Riddle
Lennie was cleaning up some old papers in his office and found a list with the following names:
Washington
Jefferson
Lincoln
Hamilton
Jackson
Grant
The last name on the list was mostly worn away and he couldnt make it out. What was the last name and why?
Washington
Jefferson
Lincoln
Hamilton
Jackson
Grant
The last name on the list was mostly worn away and he couldnt make it out. What was the last name and why?
Hint:
Franklin. Its a list of the men on U.S. currency, $1, $2, $5, $10, $20 and $50. The $100 bill has Franklin. And an interesting tidbit is that Hamilton, along with Franklin, are the only two men in the list who did not serve as president. Did you answer this riddle correctly?
YES NO
YES NO
5 Houses Riddle
There are 5 houses that have 5 occupants. Each occupants house is differently colored. The houses also have different choice of beverages, different cigarette brands, and a unique pet. Your goal is to figure out which occupant owns the fish....
Here's more information:
An Englishman resides in a red house.
The Dane drinks tea.
Dogs are kept by the Swede.
The green house is left to the white house.
The occupant of the green house drinks coffee.
The birds are kept by the Pall Mall smoker.
The horse keeper and the Dunhill smoker live next to each other.
The German smokes Prince.
The Norwegian lives right next to the blue house.
The blend smoker's neighbor drinks water.
Here's more information:
An Englishman resides in a red house.
The Dane drinks tea.
Dogs are kept by the Swede.
The green house is left to the white house.
The occupant of the green house drinks coffee.
The birds are kept by the Pall Mall smoker.
The horse keeper and the Dunhill smoker live next to each other.
The German smokes Prince.
The Norwegian lives right next to the blue house.
The blend smoker's neighbor drinks water.
Hint:
Obama's Poop Riddle
Hint:
He has so many liberals around his butt sniffing it all up. Did you answer this riddle correctly?
YES NO
YES NO
The Nurses Office Riddle
Hint:
The Four Digit Number Riddle
Can you find the four digit number in which the first digit is one fourth of the last digit, the second digit is 6 times the first digit, and the third digit is the second digit plus 3?
Hint:
Party Poison Riddle
In a party, two friends ordered single malt whiskey on the rocks. One of them drank five of the same in the time when his friend was able to drink only one. Immediately after, his friend died. However the other one was feeling completely normal.
Both the drinks were poisoned. How did the guy who drink five glasses survived?
Both the drinks were poisoned. How did the guy who drink five glasses survived?
Hint:
The guy who drank five glasses survived because the poison was in the middle of ice cubes. He drank rapidly and thus the ice had no chance to melt in his drink while the other one drank slowly and thus enough ice had melted in his drink to poison it heavily and he died. Did you answer this riddle correctly?
YES NO
YES NO
Power Outage Riddle
Julie is going on an extended trip for three weeks. She lives in a remote area where there are frequent electrical power outages which can last up to three or four days. Julie has quite a bit of food in her freezer which would go bad if it thawed and then re-froze. She does have digital clock and a VCR which would flash 12:00 if the power went out. Unfortunately the clock and VCR flash even if the power only goes out for a few seconds. What can Julie do so that when she returns home she will be able to determine whether the power was out long enough to thaw her food? Asking a neighbor whether the power was out, isn't a reliable option because the nearest house is half a mile away, and one house may have power, while another house may have no power. She won't be able to have a neighbor check on her house every day, and has no one to house sit.
Hint:
One thing Julie could do is freeze a tray of ice-cubes, and turn the tray of ice upside down in her freezer. When she comes home, she should check the tray. If the ice cubes are still in the tray, the food is safe to eat. If the trays are empty, it's time to clean out the freezer. She will have to make a judgment call if the ice-cubes are only slightly thawed. Did you answer this riddle correctly?
YES NO
YES NO
An Obnoxious Pumpkin Riddle
Hint:
Penguin Navy Riddle
Hint:
The Dinner Party Riddle
You and your wife organize a dinner party. You invite four other husband-wife couples. You and your wife don't necessarily know everyone you invited. Once everyone is at the party, the people who don't know each other yet shake hands with each other. You can assume that everyone knows their own wife/husband, and that no one shakes their own hand.
After this happens, you ask each person, except for yourself, how many people they shook hands with. Everybody tells you a different number.
How many people did your wife shake hands with?
After this happens, you ask each person, except for yourself, how many people they shook hands with. Everybody tells you a different number.
How many people did your wife shake hands with?
Hint:
Your wife shook hands with 4 people
If everybody shook hands with a different number of people, then the most any person shook hands with was 8 people, and in fact, a single person must have shaken hands with exactly 8 people. Figure out exactly who this person did - and didn't - shake hands with. Then go from there. Did you answer this riddle correctly?
YES NO
If everybody shook hands with a different number of people, then the most any person shook hands with was 8 people, and in fact, a single person must have shaken hands with exactly 8 people. Figure out exactly who this person did - and didn't - shake hands with. Then go from there. Did you answer this riddle correctly?
YES NO
Prince Age Riddle
A princess is as old as the prince will be when the princess is twice the age that the prince was when the princess's age was half the sum of their present ages.
What are their ages?
What are their ages?
Hint:
Current Future Past
Princess x 2z (x+y)/2
Prince y x z
I then created three equations, since the difference in their age will always be the same.
d = the difference in ages
x y = d
2z x = d
x/2 + y/2 z = d
I then created a matrix and solved it using row reduction.
x y z
1 -1 0 d
-1 0 2 d
.5 .5 -1 d
It reduced to:
x y z
1 0 0 4d
0 1 0 3d
0 0 1 5d/2
This means that you can pick any difference you want (an even one presumably because you want integer ages).
Princess age: 4d
Prince age: 3d
Ages that work
Princess:
4
8
16
24
32
40
48
56
64
72
80
Prince:
3
6
12
18
24
30
36
42
48
54
60 Did you answer this riddle correctly?
YES NO
Princess x 2z (x+y)/2
Prince y x z
I then created three equations, since the difference in their age will always be the same.
d = the difference in ages
x y = d
2z x = d
x/2 + y/2 z = d
I then created a matrix and solved it using row reduction.
x y z
1 -1 0 d
-1 0 2 d
.5 .5 -1 d
It reduced to:
x y z
1 0 0 4d
0 1 0 3d
0 0 1 5d/2
This means that you can pick any difference you want (an even one presumably because you want integer ages).
Princess age: 4d
Prince age: 3d
Ages that work
Princess:
4
8
16
24
32
40
48
56
64
72
80
Prince:
3
6
12
18
24
30
36
42
48
54
60 Did you answer this riddle correctly?
YES NO
100 Offices Riddle
A new medical building containing 100 offices had just been completed. Mark was hired to paint the numbers 1 to 100 on the doors. How many times will Mark have to paint the number nine?
Hint:
Did you say three? The correct answer is twenty (29, 39, and so on). Did you answer this riddle correctly?
YES NO
YES NO
The Chess Player Riddle
Hint:
Add Your Riddle Here
Have some tricky riddles of your own? Leave them below for our users to try and solve.