Find the next number in the sequence

5 12 24 36 ?

Three people enter a room and have a green or blue hat placed on their heads. They cannot see their own hat but can see the other hats.
The colour of each hat is purely random. They could all be green, blue, or any combination of green and blue.
They need to guess their own hat colour by writing it on a piece of paper, or they can write 'pass'.
They cannot communicate with each other in any way once the game starts. But they can have a strategy meeting before the game.
If at least one of them guesses correctly they win $10,000 each, but if anyone guesses incorrectly they all get nothing.
What is the best strategy?

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?

I noticed one of the words in the oxford dictionary is spelled incorrectly. What about you?

1. How can we put an elephant in the refrigerator?
2. How can we put a Giraffe in a refrigerator?
3. The king of the jungle invites all the animals to a party everyone comes except for one animal, which animal?
4. You come to a crocodile-infested lake, you can't go around it, you can't co under it and you can't go over it, how do you get across?

He loves to dance, twist and prance, he shakes his tail, and as a way he sails, wingless he flies into the sky. What is he?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

Eight of us go fourth, not back, to protect our king from an attack. What are we?

I have 50 feet long of cloth, I need to create 50 handkerchiefs each size of 1 foot. I take one minute to cut a 1-foot handkerchief. So how long will it take to cut 50 handkerchiefs?