What word begins and ends with an E, but has only one letter?

If you say my name, I will no longer exist. What am I?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

An exterior architect is asked by a builder to plant seven trees in a manner that there are exactly six rows of trees in a straight line and each row has three trees in particular.

How will he do it?

Mr. Buttons was all set to go to the village of Buttonland to meet his friend. So, he packed his bags and left for the village at 5 in the morning. Upon travelling on a road for miles, he came across a point where the road diverged into two. He was confused on which road to take. He gazed around and he saw two owls sitting on a branch. He thought he could ask for directions for the village from the two owls. So he went to the tree. There he saw a sign which read, "One owl always lies, and one is always truthful. They both fly away if you ask them more than 1 question."
Mr. Buttons was caught in the dilemma of what to ask? And from which owl to ask, since he only had one question. What should Mr. Buttons ask?

Suppose we lay down two cups in front of you. One of the cups is filled with tea and the other one with coffee. Now we ask you to take a spoonful of tea and mix it with the coffee. At this moment, the coffee cup has a mixture of tea and coffee. You have to take that mixture (spoonful) and add it back to the tea.

Can you now tell if the cup of coffee has more tea or the cup of tea has more coffee?

Jim has three close friends at his school: Michael, John and Alice. Two of them play football, two play basketball and two play hockey. The friend who does not play hockey does not play basketball as well. The friend who does not play football does not play hockey.

Can you identify which sport/s is played by which person?

There is a wide field of corn. A goose finds its way into the field and starts running. Can you find out till which point the goose can run into the field?

Replace the question mark with the correct number in the below-given picture?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?