Which Burger Is Different in below image?

How many sides does a circle have?

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

During which month do people sleep the least?

I am white when I am dirty, and black when I am clean. What am I?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

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

A man started to town with a fox, a goose, and a sack of corn. He came to a stream which he had to cross in a tiny boat. He could only take one across at a time. He could not leave the fox alone with the goose or the goose alone with the corn. How did he get them all safely over the stream?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?