Take a Challenge

Logic and Interview Questions

What Number is A?

Look closely and take your time. People have a tendency to over think some of the basic household concepts.

Heads or Tails?

You have 100 coins laying flat on a table, each with a head side and a tail side. 10 of them are heads up, 90 are tails up. How would you split the coins into two piles such that there are the same number of heads in each pile? You can't see, feel or use your senses in any way to see which side is up.

Can You Tell Time?

How many times a day do the minute and hour hands of a clock overlap?

How Many Matches Must Be Played?

There are 3,182 players in a head-to-head knockout tennis tournament. How many matches must be played to crown a winner?

Will You Lose Your Head?

You've stumbled into a topless bar and before long you awake at a table with other patrons, you notice a headless body in the corner of the room. There is a six chamber revolver on the table and a man explaining the rules of the game about to be played. The six chamber revolver will be loaded with two bullets side by side, the other chambers will remain empty and the cylinder will then be spun. After one player takes a shot the next player will have the option pull the trigger again or to spin the revolver before pulling. Next thing you know the patron next to you has the gun to his head and pulls the trigger, *click*, nothing happens. Now the gun is passed to you. Should you pull the trigger again or spin the chamber before pulling the trigger?

Can You Get a Matching Pair?

Your sock drawer contains 11 red socks and 15 blue socks. Your light isn't working and you must select your socks without seeing them. What is the minimum number of socks you need to take from your drawer and carry to a well-lit room to guarantee at least a matching pair?

Buckets of Water

You are given a five gallon bucket, a three gallon bucket, and an unlimited supply of water. How can you exactly measure four gallons of water?

Can You Catch The Cheat?

A king demands a tax of 1,000 gold coins from each of 10 regions in his nation. The tax collector for each region brings him the requested bag of gold coins at year end. An informant tells the king that one tax collector is cheating and giving coins that are consistently 10% lighter than they should be, but he does not know which collector is cheating. The king knows that one coin should weigh exactly one ounce. How can the king identify the cheat by using a weighing device exactly once?

How Many Degrees?

What is the angle (if any) between the hour and minute hands of a clock when the time is 9:45?

Will You Be Burned Alive?

A man is set to be burned at the altar of truth or the altar of untruth - they let him know he can make one statement. If it is true he will be burnt at the altar of truth and if it is untrue he will be burnt at the altar of untruth. He makes a statement and they let him go. What did he say?

How Many Micro-Cubes Have Fallen?

Picture a 10 x 10 x 10 "macro-cube" floating. The macro-cube is composed of 1 x 1 x 1 "micro-cubes", all stuck together. Through some damage, the exposed (outermost) layer of micro-cubes loosen and fall to the ground. How many micro-cubes are on the ground?

How quickly can you cross the bridge?

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?

Can You Pay The Right Amount?

You hire a man to work in your kingdom for seven days. You wish to pay him in gold. You have one gold bar that can break into seven equal parts, same height and width. You wish to pay him one gold part per day, but you may only snap the bar in only two places. Where do you snap the bar so that you may pay him at the end of each day, and so that on the successive days he may use what you paid him previously to make change?

Looking Through The Mirror

Why are images in a mirror flipped horizontally and not vertically? For example, although I wear a watch on my left hand, and my reflection wears his on his right hand, my reflection is not standing on his head.

The Countdown

You have a string-like fuse that burns in exactly one minute. The fuse is inhomogeneous, it may burn slowly, then quickly, then slowly, and so on. You have a match and no watch. How can you measure exactly 30 seconds?

How Much Will You Spend?

You receive eight balls. They are identical except that one is heavier than the rest. You have access to a scale but it cost $10 per use. What is the least amount you can spend to find which ball is the heaviest and how?

Can you Correct The Labels?

There are three boxes, one contains only apples, one contains only oranges, and one contains both apples and oranges. The boxes have been incorrectly labeled such that no label identifies the actual contents of the box it labels. Opening just one box, and without looking in the box, you take out one piece of fruit. By looking at the fruit, how can you immediately label all of the boxes correctly? Which box should you choose from?

How Long To Reach The Top?

A snail is climbing a 10-foot flag pole. He climbs up three feet every 45 minutes. He likes to take naps for 15 minutes after climbing. While sleeping, he slides down by one foot. How long until he reaches the top of the pole?

Can You Crack The Safe?

You're trying to crack a three-number dial safe. Without knowing the combination numbers, what is the maximum number of trials required to open the safe? A trial is considered a full three-number combination. There are 40 numbers on this safe. To enter a combination you start with the dial at zero and turn counter-clockwise until the first number, then clockwise back to zero, then clockwise to the second number, then counter-clockwise back to zero, and finally counter-clockwise to the third number. Upon the correct combination, the safe will spring open.

Rapidly Growing Lilies

You start with a single lily pad sitting on an otherwise empty pond. You are told that the surface area of the lily doubles every day and that it will take 30 days for the single lily to cover the surface of the pond. | If instead of one lily pad you start with eight lily pads (each identical in characteristics to the original lily), how many days will it take for the surface of the pond to be covered? Assume that they don't overlap each other.