Long easy logic riddles

logiccleansimple

You're walking down a path and come to two doors. One of the doors leads to a life of prosperity and happiness, and the other door leads to a life of misery and sorrow. You don't know which door is which. In front of the door is ONE man. You know that this man either always lies, or always tells the truth, but you don't know which. The man knows which door is which. You are allowed to ask the man ONE yes-or-no question to figure out which door to go through. To make things more difficult, the man is very self-centered, so you are only allowed to ask him a question about what he thinks or knows; your question cannot involve what any other person or object (real or hypothetical) might say. What question should you ask to ensure you go through the good door?
You should ask: "If I asked you if the good door is on the left, would you say yes?" Notice that this is subtly different than asking "Is the good door on the left?", in that you are asking him IF he would say yes to that question, not what his answer to the question would be. Thus you are asking a question about a question, and if it ends up being the liar you are talking to, this will cause him to lie about a lie and thus tell the truth. The four possible cases are: The man is a truth-teller and the good door is on the left. He will say "yes". The man is a truth-teller and the good door is on the right. He will say "no". The man is a liar and the good door is on the left. He will say "yes" because if you asked him "Is the good door on the left?", he would lie and say "no", and so when you ask him if he would say "yes", he will lie and say "yes". The man is a liar and the good door is on the right. Similar to the previous example, he'll say "no". So regardless of whether the man is a truth-teller or a liar, this question will get a "yes" if the door on the left is the good door, and a "no" if it's not.
73.11 %
144 votes
logiccleansimple

It was a very large truck. The truck need to cross a 20 mile long bridge. Unfortunately, the bridge can only hold the weight of 12000 lbs. Even a single pound extra, the bridge would collapse. However the weight of the truck is exactly 12000 lbs. The driver carefully drove and crossed almost 85 percent distance of the bridge. He stopped to get a small break. Suddenly, a bird landed on the truck. Did the bridge collapse? Justify your answers with explanation!
No. The bridge doesn't collapse. The truck almost crossed 85 percent of total distance. Equivalent diesel would have been lost. So the extra weight of the bridge doesn't add any extra load to the bridge.
73.05 %
71 votes
logiccleansimple

Shadow drove into the Speedy Service Station and pulled up to the pumps. "Fill it up, please," said Shadow. " This may sound strange," said the owner, "but I'd rather fill two cars from out of town than one car from this town." Shadow looked across the small town and replied, "I know just what you mean." Why would the owner feel this way?
The owner would rather fill two cars from anywhere than one car from town because he would make twice the amount of money.
73.02 %
53 votes
logictrickysimple

A man was driving a truck at 60 mph. He did not have his headlights on and the moon was not up. Yet he did not hit the woman who crossed the road. How?
He was driving the truck during daytime.
73.01 %
62 votes
logicmathtricky

You just bought a cute rabbit at a pet store. The rabbit can breed once every month, and deliver 7 babies at a time. How many rabbits do you have after 12 months?
One, it takes two rabbits to breed.
72.92 %
75 votes
logicsimplestory

A number of people have broken the sound barrier, either in a super-fast car, or in nice fancy planes. However, hundreds of years ago it was broken on horseback. How?
Many people who ride horses carry whips. They crack the whip while they ride the horse. When a whip is cracked, the tip travels faster than the speed of sound, which makes the loud snap. It actually creates a miniature sonic boom of sorts. The whip breaks the sound barrier, thus, it was broken on horseback.
72.84 %
66 votes
cleansimplelogic

I heard of an invading, vanquishing army sweeping across the land, liquid-quick; conquering everything, quelling resistance. With it came darkness, dimming the light. Humans hid in their houses, while outside spears pierced, shattering stones walls. Uncountable soldiers smashed into the ground, but each elicited life as he died. When the army had vanished, advancing northward, the land was gree and growing, refresh.
Rainstorm.
72.80 %
79 votes
logicmathtricky

Two planes take off at the same exact moment. They are flying across the Atlantic. One leaves New York and is flying to Paris at 500 miles per hour. The other leaves Paris and is flying to New York at only 450 miles per hour. Which one will be closer to Paris when they meet?
They will both the same distance from Paris when they meet!
72.80 %
79 votes