##### Easy Riddle #194 (hard)

Question: A natural state, I'm sought by all.
Go without me, and you shall fall.
You do me when you spend,
and use me when you eat to no end.

What am I?

##### Easy Riddle #557 (hard)

Question: Under pressure is the only way I work,
and by myself is the only way I'm hurt.

What am I?

##### Riddle: 100 prisoners and hats (hard)

Question: There are 100 prisoners lining up to go to jail. Each prisoner is wearing a hat that is either black or white. The prisoners don't know their own hat color, just the hat color of those in front of them in line (the first prisoner in line can't see anyone's hat and the last prisoner can see everyone's hat except their own). Starting from the back, one of the guards asks each prisoner what color their hat is. If they are correct they get to go free but if they are wrong they go to jail.If the prisoners get to discuss a plan, how can at least 99 of them be saved?

##### Easy Riddle #166 (hard)

Question: Smell me, buy me, and deliver me.
I won't change.

What am I?

##### Easy Riddle #128 (hard)

Question: There is a basket full of hats. 3 of them are white and 2 of them are black. There are 3 men Tom, Tim, and Jim. They each take a hat out of the basket and put it on their heads without seeing the hat they selected or the hats the other men selected. The men arrange themselves so Tom can see Tim and Jim's hats, Tim can see Jim's hat, and Jim can't see anyone's hat.

Tom is asked what color his hat is and he says he doesn't know.
Tim is asked the same question, and he also doesn't know.
Finally, Jim is asked the question, and he does know.

What color is his hat?