What number comes next in the series?

5 15 5 18 5 24 14 20 _

Rectify the following equality 101 - 102 = 1 by moving just one digit.

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?

How many triangles are there in the picture below?

I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

There was a competition where the contestants had to hold something. At the end of the event, the winner was a person who had no hands or feet. What was it that the contestants had to hold?

How can you take 2 from 5 and leave 4?

Why is 6 afraid of 7?

Replace the question mark with the correct number below.

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?