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?

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?

Two in a corner, one in a room, zero in a house, but one in a shelter. What am I?

Thirty friends were on a hiking trip when they decided to enjoy the bonfire. They assembled for it and agreed to play a game. For that, they divided themselves into five teams with seven members each, forming five rows.

How did they manage to achieve this formation?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

The more it dries, the wetter it becomes. Can you tell what it is?

what does this picture(rebus) riddle means ?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

On my way to St. Ives I saw a man with 7 wives. Each wife had 7 sacks. Each sack had 7 cats. Each cat had 7 kittens. Kittens, cats, sacks, wives. How many were going to St. Ives?

Can you find out who is the kidnapper in below Picture and why, Explain ?