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
Mile Long Train Riddle
A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?
Hint:
Two minutes. The back of the train would be at the beginning of the tunnel after 1 minute, and would leave the end of the tunnel at the 2 minute mark. Did you answer this riddle correctly?
YES NO
YES NO
A Train Of Two Cities
A train leaves from New York City (NYC) heading towards Los Angeles (LA) at 100 mph. Three hours later, a train leaves LA heading towards NYC at 200 MPH. Assume there's exactly 2000 miles between LA and NYC. When they meet, which train is closer to New York City?
Hint:
Five Eyes Riddle
Hint:
Electric Train Travel Riddle
If an electric train is going east at 60 miles an hour and there is a strong westerly wind, which way does the smoke from the train drift?
Hint:
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
Hot Air Balloon Over The Sahara
One sunny afternoon, three men go for a ride on a hot air balloon over the Sahara desert. An hour into the trip, the balloon begins to lose altitude. A month later, someone found one of the ballooners laying on the desert sand dead, naked, and holding half a toothpick. What happened to him?
Hint:
As the balloon lost altitude, the men took of their clothes and threw them overboard to decrease the weight of the balloon. The balloon continued to drop so the men drew straws to see who would be forced to jump. The dead man in the desert drew the shortest one (the half toothpick). Did you answer this riddle correctly?
YES NO
YES NO
Two Ships Riddle
Two ships leave the port of San Diego, both sailing for the distant shores of Japan. Each ship plans to travel the same route, spending a two-week stopover in Tokyo before returning to California. The first ship churns through the sea at 35 miles per hour throughout the entire journey. The second ship moves slower, at just 30 mph. After two weeks in Tokyo, the captain of the second ship decides to run at a faster pace, moving at 40 mph for the entire return trip. Which ship arrives in San Diego first?
Hint:
The first ship!
First ship = d/35 + d/35 = 2d/35 = 0.0571d
Second ship = d/30 = d/40 = 70d/1200 = 0.058 Did you answer this riddle correctly?
YES NO
First ship = d/35 + d/35 = 2d/35 = 0.0571d
Second ship = d/30 = d/40 = 70d/1200 = 0.058 Did you answer this riddle correctly?
YES NO
Two Ships Riddle
Two ships leave the port of San Diego, both sailing for the distant shores of Japan. Each ship plans to travel the same route, spending a two-week stopover in Tokyo before returning to California. The first ship churns through the sea at 35 miles per hour throughout the entire journey. The second ship moves slower, at just 30 mph. After two weeks in Tokyo, the captain of the second ship decides to run at a faster pace, moving at 40 mph for the entire return trip. Which ship arrives in San Diego first?
Hint:
The first ship!
First ship = d/35 + d/35 = 2d/35 = 0.0571d
Second ship = d/30 = d/40 = 70d/1200 = 0.058 Did you answer this riddle correctly?
YES NO
First ship = d/35 + d/35 = 2d/35 = 0.0571d
Second ship = d/30 = d/40 = 70d/1200 = 0.058 Did you answer this riddle correctly?
YES NO
3000 Apples
You have been given the task of transporting 3,000 apples 1,000 miles from Appleland to Bananaville. Your truck can carry 1,000 apples at a time. Every time you travel a mile towards Bananaville you must pay a tax of 1 apple but you pay nothing when going in the other direction (towards Appleland).
What is highest number of apples you can get to Bananaville?
What is highest number of apples you can get to Bananaville?
Hint:
833 apples.
Step one: First you want to make 3 trips of 1,000 apples 333 miles. You will be left with 2,001 apples and 667 miles to go.
Step two: Next you want to take 2 trips of 1,000 apples 500 miles. You will be left with 1,000 apples and 167 miles to go (you have to leave an apple behind).
Step three: Finally, you travel the last 167 miles with one load of 1,000 apples and are left with 833 apples in Bananaville. Did you answer this riddle correctly?
YES NO
Step one: First you want to make 3 trips of 1,000 apples 333 miles. You will be left with 2,001 apples and 667 miles to go.
Step two: Next you want to take 2 trips of 1,000 apples 500 miles. You will be left with 1,000 apples and 167 miles to go (you have to leave an apple behind).
Step three: Finally, you travel the last 167 miles with one load of 1,000 apples and are left with 833 apples in Bananaville. Did you answer this riddle correctly?
YES NO
Eight Eights
Hint:
How Many Times A Day?
Hint:
22 times: 12:00:00, 1:05:27, 2:10:55, 3:16:22, 4:21:49, 5:27:16, 6:32:44, 7:38:11, 8:43:38, 9:49:05, 10:54:33. Each twice a day. Did you answer this riddle correctly?
YES NO
YES NO
The Broken Grandfather Clock
A grandfather has a broken grandfather clock that is off by a minute every hour (too fast). He figures out a way, while keeping it running at the same rate, to make the clock say the correct time twice a day.
How could he do this?
How could he do this?
Hint:
The 100 Pound Watermelon
There is a 100 pound watermelon laying out in the sun. 99 percent of the watermelon's weight is water. After laying out for a few hours 98 percent of the watermelon's weight is water.
How much water evaporated?
How much water evaporated?
Hint:
50 pounds.
In the beginning it is 99 pounds water and 1 pound other stuff. At the end the 1 pound other stuff is 2 percent so the total weight is 50 pounds. 50 pounds - 1 pound other stuff = 49 pounds water. So 99 pounds - 49 pounds = 50 pounds water lost. Did you answer this riddle correctly?
YES NO
In the beginning it is 99 pounds water and 1 pound other stuff. At the end the 1 pound other stuff is 2 percent so the total weight is 50 pounds. 50 pounds - 1 pound other stuff = 49 pounds water. So 99 pounds - 49 pounds = 50 pounds water lost. Did you answer this riddle correctly?
YES NO
All I Do Is Wander And Devour
I'm tall and I'm skinny, and yet very shy.
I live just an hour then, as quickly, I die.
All that I do in my one given hour
is wander a trail and all things devour.
When e'er people see me, they never are glad,
but when I depart them, they're never more sad.
I live just an hour then, as quickly, I die.
All that I do in my one given hour
is wander a trail and all things devour.
When e'er people see me, they never are glad,
but when I depart them, they're never more sad.
Hint:
Add Your Riddle Here
Have some tricky riddles of your own? Leave them below for our users to try and solve.