You knock a Table over in the library, and suddenly 20 eyes are looking at you.

How can you write nineteen in a manner that if we take out one, it becomes twenty?

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.

1 rabbit saw 9 elephants while going to the river. Every elephant saw 3 monkeys going toward the river. Each monkey had 1 parrot in each hand. How many animals are going towards the river?

I’m tall when I’m young, and I’m short when I’m old. What 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?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

I’m orange, I wear a green hat and I sound like a parrot. What am I?

Fate has decided that you will only be pleased to meet me when you need me

Maybe that is why, when I am working, I start working

However annoying I may be to the regulars, the little ones are always inspired

I will always be waiting if you try to reach me

How many of you can guess my name, let me see

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?