Under The Cup Riddle
You decide to play a game with your friend where your friend places a coin under one of three cups. Your friend would then switch the positions of two of the cups several times so that the coin under one of the cups moves with the cup it is under. You would then select the cup that you think the coin is under. If you won, you would receive the coin, but if you lost, you would have to pay.
As the game starts, you realise that you are really tired, and you don't focus very well on the moving of the cups. When your friend stops moving the cups and asks you where the coin is, you only remember a few things:
He put the coin in the rightmost cup at the start.
He switched two of the cups 3 times.
The first time he switched two of the cups, the rightmost one was switched with another.
The second time he switched two of the cups, the rightmost one was not touched.
The third and last time he switched two of the cups, the rightmost one was switched with another.
You don't want to end up paying your friend, so, using your head, you try to work out which cup is most likely to hold the coin, using the information you remember.
Which cup is most likely to hold the coin?
As the game starts, you realise that you are really tired, and you don't focus very well on the moving of the cups. When your friend stops moving the cups and asks you where the coin is, you only remember a few things:
He put the coin in the rightmost cup at the start.
He switched two of the cups 3 times.
The first time he switched two of the cups, the rightmost one was switched with another.
The second time he switched two of the cups, the rightmost one was not touched.
The third and last time he switched two of the cups, the rightmost one was switched with another.
You don't want to end up paying your friend, so, using your head, you try to work out which cup is most likely to hold the coin, using the information you remember.
Which cup is most likely to hold the coin?
Hint: Write down the possibilities. Remember that there are only three cups, so if the rightmost cup wasn't touched...
The rightmost cup.
The rightmost cup has a half chance of holding the coin, and the other cups have a quarter chance.
Pretend that Os represent cups, and Q represents the cup with the coin.
The game starts like this:
OOQ
Then your friend switches the rightmost cup with another, giving two possibilities, with equal chance:
OQO
QOO
Your friend then moves the cups again, but doesn't touch the rightmost cup. The only switch possible is with the leftmost cup and the middle cup. This gives two possibilities with equal chance:
QOO
OQO
Lastly, your friend switches the rightmost cup with another cup. If the first possibility shown above was true, there would be two possibilities, with equal chance:
OOQ
QOO
If the second possibility shown above (In the second switch) was true, there would be two possibilities with equal chance:
OOQ
OQO
This means there are four possibilities altogether, with equal chance:
OOQ
QOO
OOQ
OQO
This means each possibility equals to a quarter chance, and because there are two possibilities with the rightmost cup having the coin, there is a half chance that the coin is there. Did you answer this riddle correctly?
YES NO
The rightmost cup has a half chance of holding the coin, and the other cups have a quarter chance.
Pretend that Os represent cups, and Q represents the cup with the coin.
The game starts like this:
OOQ
Then your friend switches the rightmost cup with another, giving two possibilities, with equal chance:
OQO
QOO
Your friend then moves the cups again, but doesn't touch the rightmost cup. The only switch possible is with the leftmost cup and the middle cup. This gives two possibilities with equal chance:
QOO
OQO
Lastly, your friend switches the rightmost cup with another cup. If the first possibility shown above was true, there would be two possibilities, with equal chance:
OOQ
QOO
If the second possibility shown above (In the second switch) was true, there would be two possibilities with equal chance:
OOQ
OQO
This means there are four possibilities altogether, with equal chance:
OOQ
QOO
OOQ
OQO
This means each possibility equals to a quarter chance, and because there are two possibilities with the rightmost cup having the coin, there is a half chance that the coin is there. Did you answer this riddle correctly?
YES NO
The Traffic Light Riddle
There is a traffic light at the top of a hill. Cars can't see the light until they are 200 feet from the light.
The cycle of the traffic light is 30 seconds green, 5 seconds yellow and 20 seconds red.
A car is traveling 45 miles per hour up the hill.
What is the probability that the light will be yellow when the driver first crests the hill and that if the driver continues through the intersection at her present speed that she will run a red light?
The cycle of the traffic light is 30 seconds green, 5 seconds yellow and 20 seconds red.
A car is traveling 45 miles per hour up the hill.
What is the probability that the light will be yellow when the driver first crests the hill and that if the driver continues through the intersection at her present speed that she will run a red light?
Hint:
The probability of the driver encountering a yellow light and the light turning red before the car enters the intersection is about 5.5%.
At 45 mph the car is traveling at 66 feet/second and will take just over 3 seconds (3.03) to travel the 200 feet to the intersection. Any yellow light that is in the last 3.03 seconds of the light will cause the driver to run a red light.
The entire cycle of the light is 55 seconds. 3.03/55 = 5.5%. Did you answer this riddle correctly?
YES NO
At 45 mph the car is traveling at 66 feet/second and will take just over 3 seconds (3.03) to travel the 200 feet to the intersection. Any yellow light that is in the last 3.03 seconds of the light will cause the driver to run a red light.
The entire cycle of the light is 55 seconds. 3.03/55 = 5.5%. Did you answer this riddle correctly?
YES NO
A Man Pushes His Car
Hint:
What Remains When The Roads Are Gone Riddle
A race car driver has completed 12 1/2 laps of a 50-lap race. What fractional part of the race remains?
Hint:
Let's take a look at the explanation of the riddle.
As per the total laps in the race are 50 and the driver has completed 12 1/2 laps. This means, we have to subtract 12 1/2 from the total 50 laps. This equal to 37 1/2 or 37.5
50 - 12 1/2 = 37 1/2 or 37.5
Now, we need to calculate the fractional part of the race remains. For this, we need to divide the remaining laps by total laps, that is, 37 1/2 divide by 50 or 37.5 divided by 50 which will be equal to 0.74 or 3/4.
37 1/2 / 50 = 0.74 or 3/4
Hence, the right answer to the riddle is 3/4 Did you answer this riddle correctly?
YES NO
As per the total laps in the race are 50 and the driver has completed 12 1/2 laps. This means, we have to subtract 12 1/2 from the total 50 laps. This equal to 37 1/2 or 37.5
50 - 12 1/2 = 37 1/2 or 37.5
Now, we need to calculate the fractional part of the race remains. For this, we need to divide the remaining laps by total laps, that is, 37 1/2 divide by 50 or 37.5 divided by 50 which will be equal to 0.74 or 3/4.
37 1/2 / 50 = 0.74 or 3/4
Hence, the right answer to the riddle is 3/4 Did you answer this riddle correctly?
YES NO
The 6 Wheeled Fly Riddle
Hint:
Driving Away Riddle
Hint:
Cat License Riddle
Hint:
Benzene Ring Riddle
Hint:
Working After Being Fired Riddle
Hint:
A Riddle About Transport
Here is a riddle about transport
So it is time to use your brain
This has an engine and carriages
And runs on rails it's a_______?
So it is time to use your brain
This has an engine and carriages
And runs on rails it's a_______?
Hint:
I Have Many Rings Riddle
Im full of gas but Im not a car
I have many rings but Im not a jewelry store
Im a Roman god but Im not Janus
Im a large planet but Im not Jupiter
What am I?
I have many rings but Im not a jewelry store
Im a Roman god but Im not Janus
Im a large planet but Im not Jupiter
What am I?
Hint:
Yogi Bear Riddle
Hint:
Because when he tried to make a second one he made a Boo-Boo Did you answer this riddle correctly?
YES NO
YES NO
Discharge Of The Rifle
Anderson, Biggs, and Carpenter were staying together at a place by the seaside. One day they went out in a boat and were a mile at sea when a rifle was fired on shore in their direction.
It seems that Anderson only heard the report of the gun, Biggs only saw the smoke, and Carpenter merely saw the bullet strike the water near them. Which of them first knew of the discharge of the rifle?
It seems that Anderson only heard the report of the gun, Biggs only saw the smoke, and Carpenter merely saw the bullet strike the water near them. Which of them first knew of the discharge of the rifle?
Hint:
Biggs, who saw the smoke, would be first; Carpenter, who saw the bullet strike the water, would be second; and Anderson, who heard the report, would be last of all. Did you answer this riddle correctly?
YES NO
YES NO
Name A Word Riddle
Hint:
Crossing The River Safely Riddle
A man is traveling with a fox and two chickens. If he leaves the fox alone with the chickens, the fox will eat the chickens. He comes to a river and needs to cross it. He finds a small boat that can carry only him and one animal. How does he get himself, the fox and two chickens across the river safely?
Hint:
Take the fox over, return with nothing. Go over with one chicken, return with the fox. Go over with the second chicken, return with nothing. Finally, take the fox over. Did you answer this riddle correctly?
YES NO
YES NO
Add Your Riddle Here
Have some tricky riddles of your own? Leave them below for our users to try and solve.