Four people need to cross a rickety rope bridge to get back to their camp at night. Unfortunately, they only have one flashlight and it only has enough light left for seventeen minutes. The bridge is too dangerous to cross without a flashlight, and it’s only strong enough to support two people at any given time. Each of the campers walks at a different speed. One can cross the bridge in 1 minute, another in 2 minutes, the third in 5 minutes, and the fourth takes 10 minutes to cross.
How do the campers cross the bridge in 17 minutes? Riddle Answer
You have a set of 3 light switches outside a closed door. One of them controls the incandescent light bulb inside the room. With the door closed from outside the room, you can turn the light switches on or off as many times as you would like.
You can go into the room – one time only – to see the light. You cannot see whether the light is on or off from outside the room, nor can you change the light switches while inside the room.
No one else is in the room to help you. The room has no windows.
Based on the information above, how would you determine which of the three light switches controls the light inside the room? Riddle Answer
A frog is at the bottom of a 30 meter well. Each day he summons enough energy for one 3 meter leap up the well.
Exhausted, he then hangs there for the rest of the day. At night, while he is asleep, he slips 2 meters backwards.
How many days does it take him to escape from the well? Riddle Answer
A cable of 80m (meters) is hanging from the top of two poles that are both 50m from the ground.
What is the distance between the two poles, to one decimal place, if the center of the cable is 10m above the ground? Riddle Answer
Your friend has 100 red marbles, 100 blue marbles and 2 jars.
He proposes a game. He fills the jars with the marbles, put the two jars behind his back and tell you to pick one of them at random. You’ll then close your eyes, he’ll hand you the jar you picked, and you’ll pick a random marble from that jar.
You win if the marble you pick is blue, and you lose otherwise.
To give you the best shot at winning, your friend gives you the two jars before the game starts and says you can move the marbles around however you’d like, as long as all 200 marbles are in one of the 2 jars (that is, you can’t throw any marbles away).
How should you move the marbles around to give yourself the best chance of picking a blue marble? Riddle Answer