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

How many letters are in the alphabet?

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

The first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?

You can find some missing letters in the picture. By placing two particular letters in the spaces, you can form a nine lettered word beginning from one of the corners and going clockwise direction to the middle. Can you find out the letters and the word?

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?

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

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

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

What has many keys but can’t open a single lock?