I have an eye but still cannot see.

Who am I?

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.

I can sizzle like bacon,
I am made with an egg,
I have plenty of backbone, but lack a good leg,
I peel layers like onions, but still remain whole,
I can be long, like a flagpole, yet fit in a hole.

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word 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?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

If a wheel has 54 spokes, how many spaces are there between the spokes?

What is more useful when it is broken?

How can you take 2 from 5 and leave 4?