A super hard riddle, I couldn't figure it out?

[tNikki]

This is a really hard riddle, and I couldn't figure it out... someone had to tell me the answer. Okay, here we go.


There are 10 prisoners. The cops make a deal with them. The prisoners will be put in a single file line, one behind another. Then the cops would put a hat on each of the men. The hat was either black or white, and the prisoner would have to guess the color of his hat. If he got it right, he would be free to go. But if he got it wrong, he would be killed right there.

Now after having told the men this, the cops put them all in a room together for one hour and let them talk about what to do. All 10 men agree that they should do whatever possible to save as many lives as possible.

Once they're lined up, they can't talk, or cough or do anything like that. The only noise allowed is saying what color you think your hat is.
Also, you can see everyone in front of you.The man at the back of the line, number 10, can see every ones hat but his own, and the guy in the front of the line, number 1, can't see anyone elses hat. Number 5 would be able to see the 4 people in front of him, etc.

My friend was able to save 9 lives for sure, and there was a 50 50 chance that all 10 would be saved.

What would you do, and how do you think that they were saved? Star if you like?

:]

I will post the answer later.
Oh yeah I forgot to say this, sorry. But it's not tapping or making noise... the only noise allowed is stating what color hat you think you have. There's no cough, sneeze, yawn, tap, or anything like that.
Tricky tricky :]

[Unregistered]

the one at the back of the line shouted the one in front of him his hat then the other one shoted etc but the one of the back of the line died

[Unregistered]

did the one at the back of the line shouted the one in front of him his hat then the other one shouted etc but the one of the back of the line died.

[Unregistered]

Breathing. The person would breath on the one in front either one or two times declaring black or white, that way no noise was made and no physical contact

[Unregistered]

the one in the back acted like all the men i the front and when it was his turn he guested the wrong thing and was killled

[Unregistered]

everyone besides me is wrong. the 10th person in line says black if there is an even number of black hats that he can see and white if there is an odd number of black hats in front of him. lets say the 10th person said black.

the 9th person then counts the number of black hats he can see and if there is an odd number then he knows he must have a black hat on because the 10th person said there was an odd number of black hats he could see.

the same works for the next person except he has to incorporate that the person behind him already went.