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

Count the number of triangles in the below picture?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

The chance of Mr John winning the lottery is 10%. All participants lined up and Mr John is 4th in the row. The first three participants lose the lottery.

What is the chance of Mr John now?

Today is John's birthday.
A year ago, John had five candles and he lit all the candles except the one at the last.
Now he is going to light all the candles.

How old is John Today?

(He is not five today.....)

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

Name a key which is hardest to turn.