How many times do a clock's hands overlap in a day ?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

How many words can a pen with half refill write?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

In Greek mythology, the Sphinx sat outside of Thebes and asked this riddle of all travellers who passed by. If the traveller failed to solve the riddle, then the Sphinx killed him/her. And if the traveller answered the riddle correctly, then the Sphinx would destroy herself. The riddle:

What goes on four legs in the morning, on two legs at noon, and on three legs in the evening?

Oedipus solved the riddle, and the Sphinx destroyed herself.

What do you get if you add 2 to 100 four times?

Christina is practising her dance steps along with her friends. In a particular sequence, all of them form a row. At that point, Niharika is standing in the 4th position from either end of the row.
Can you find out how many girls are practising together?

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?

Can you write down eight eights so that they add up to one thousand?

A man in a car saw a Golden Door, Silver Door and a Bronze Door. What door did he open first?