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

Replace the question mark in the picture below.

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

What is more useful when it is broken?

Which alphabet letter is a question?

What is the word or phrase?

A high school has a strange principal. On the first day, he has his students perform an odd opening day ceremony:

There are one thousand lockers and one thousand students in the school. The principal asks the first student to go to every locker and open it. Then he has the second student go to every second locker and close it. The third goes to every third locker and, if it is closed, he opens it, and if it is open, he closes it. The fourth student does this to every fourth locker, and so on. After the process is completed with the thousandth student, how many lockers are open?

What has many keys but can’t open a single lock?

What four weights can be used to balance from 1 to 30 pounds?

What is red and smells like blue paint?