Which is Odd One Out and why?

4377

3954

9862

8454

9831

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

You see me once in June, twice in November, and not at all in May. What am I?

What number should come in place of the question mark below?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

There is a box in which distinct numbered balls have been kept. You have to pick two balls randomly from the lot.

If someone is offering you a 2 to 1 odds that the numbers will be relatively prime, for example
If the balls you picked had the numbers 6 and 13, you lose $1.
If the balls you picked had the numbers 5 and 25, you win $2.

Will you accept that bet?

Can you find out a way through which you can make five squares out of the given figure by moving just six match sticks?

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

What is the word or phrase below?
R | E | A | D