How can one talk without saying a single word?

There was a greenhouse.
Inside the greenhouse, there is a white house.
Inside the white house, there is a red house.
Inside the red house, there are lots of babies.

What is It?

When can we add 2 to 11 and get 1 as the correct answer?

Prove that twice of ten is the same as twice of eleven.

If I put in one canary per cage, I have one bird too many. If I put in two canaries per cage, I have one cage too many. How many cages and canaries do I have?

A clock loses 10 minutes each hour. If the clock is set correctly at noon, what time is it when it reads 3 PM?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

How is a fly different from a mosquito?

I welcome the day with a show of light, I stealthily came here in the night. I bathe the earthy stuff at dawn, But by noon, alas! I'm gone.

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?