Why is 6 afraid of 7?

Can you find the odd number in the following?

2716, 4135, 5321 and 7145

Jack was having a candle light dinner with his girlfriend. Suddenly a cold gush of wind entered through the open window and three of the ten candles were extinguished. Assuming that none of the other candles were extinguished.

How many candles are they left with in the end ?

Using the clues below, what four numbers am I thinking of?

The sum of all the numbers is 31.
One number is odd.
The highest number minus the lowest number is 7.
If you subtract the middle two numbers, it equals two.
There are no duplicate numbers.

What are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

Can you count the number of quadrilaterals in the picture below?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?