What is black when you buy it, red when you use it, and gray when you throw it away?

I am working in a bus company. The company recently went under expansion and therefore there was not enough room for all the buses. As a result, twelve buses had to be stored outside.

If the company decides to expand the garage space by forty percent, enough space to accommodate the current buses will be created leaving enough space for twelve more buses if the need arises in future.

Can you calculate the number of buses that the company owns at present?

I am the largest in my family of fifty.
The youngest of our family lives separately from the rest of the family and so do I.
I am regarded as harsh and tough.
I am so large, you cut me in two equal halves,
each half would still be larger than the second largest member of the family.
Who am I?

How many minutes are there in Feb 2017?

Note: The shortest answer is the correct answer.

What question can you never answer yes to?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

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

How is this possible?

A man is found unconscious in front of a store at two in the morning. His head is bleeding and there’s a brick laying next to him. When the police arrive, they carry the man to jail. Why did they arrest him?

Which English verb becomes past tense just by rearranging the letters?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?