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?

What demands an answer, but asks no questions

Readers with high attention to detail can spot the mistake in the stack of shoes in 5 seconds. Are you one of them? Test your visual skills now!

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?

Twice ten are six of us,

Six are but three of us,

Nine are but four of us;

What can we possibly be?

Would you know more of us?

Twelve are but six of us,

Five are but four, do you see?

What are we?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

Samuel was out for a walk when it started to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?