what is the probability of a cat eating salmon out of my hands?

Depends on the cat. Even a pet cat may be cautious about taking food from you but some will (mine would depending on the food. She liked whitebait and flame grilled crisps (and before everyone goes mental she never had more than 1 small crisp and it wasn't very often.) But she would not take cat food from my hands - she'd hiss at me instead

If it's not your cat probably not. I've found a lot of cats to be cautious of me when I walk past even if I go to their level and put my hand down for them to sniff first. Many aren't interested in strangers.

Our cats both take food from our hands. That's how they learned not to bite.

A stray cat that has been socialized with humans might also take food from your hand but a truly feral cat will not.

definitely probable. just sit quietly, put some of the salmon in your hand, and let the cats come to you. they will eat from your hand.

Very high!!

Many cats wont take food out of hands. The reason lies in the shape of their pupil making close distance eyesight not as good as long distance/low light sight.

Cats love salmon, havent found one that did not. If this is a wild cat, chances are nill. Feed it from the ground/dish and move your distance closer. Over time you will gain enough trust that the cat may let you pet it.

If the cat is friendly then yes definitely, I hand feed one of my cats all the time, but the other one won't eat the food unless i put it down. So it all depends on the cat, if it is used to human interaction, and its personality. But hey no harm in trying, right.

No outside cat would do it.