Solve below rebus puzzle?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

What does this below rebus puzzle mean?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

Replace the question mark with the correct number.

What is always in front of you but can’t be seen?

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?

The measurement of time, That can't be found on a clock, But can be looked upon on a map.

Who is He ?

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

A red house is made out of red bricks. A yellow house is made out of yellow bricks. And, a blue house is made out of blue bricks. So, what is a greenhouse made of?