What will you call your mother's brother's brother-in-law?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Why is the Hole below a Lock?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

With the help clues provided in the image, can you find the 5 digit key?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

The more you take me, the more you leave me behind.
Who Am I?

Can you find the odd number in the following?

2716, 4135, 5321 and 7145