A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

I know a nine-letter word having only one vowel.
Do you ?

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?

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?

I am soft and cuddly that soothe your heart. But, If you pick my last name I am going to tear you all apart. Who am I?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

I am the fastest animal but cannot climb the tree. What am I?

The more you take me, the more you leave me behind.
Who Am I?