Very vague in your example in the question..
IF you make one bet $50 STRAIGHT TRIFECTA (1-2-8 ) and the horses finish 1 in first, 2 in second , and 8 in third and the payout for $1.00 wager is $ 17.20. Your ticket would pay ( $ 17.20 X 50 times ) or $860.00 .. Your $50 investment wager would be incorporated in that payoff... you show a profit of $ 810.00
If your $50.00 total wager in trifectas are a lot of different types of combinations and styles..
$1 TRIFECTA BOXES
1,2,8 tri box = $6
2,4,8 tri box = $6
2,5,8 tri box = $6
$2 Trifecta key wheel
2 with 1,4,8 with 1,4,8 = $12
2 with 1,5,8 with 1,5,8 = $12
$8 Straight Trifecta
2-8-1 = $8
Race result is 1 - 2 - 8 and the $1 payout is $17.20
The only WINNING TICKET you have is the first $1 trifecta box and that would pay you $17.20. You get your $6 back in the $17.20 payout .. thus that ticket shows a profit of $11.20
The rest of the tickets are losers to you.
NOW on Win bets.
You put $100.00 to win on one horse that has final odds of 1-1.
If the horse wins, the odds read for every $1 wagered you get $1. plus the wagered amount. So $100 Win bet will pay $200. and maybe a little extra.
You put the $100, on one horse with final odds of 3-1 and that horse wins.... the odds read for every $1 wagered you get $3. plus your wagered $1 back 3-1 odds pays $ 8.00 minimum up to $ 8.90
So $100 to win on one horse that pays $8. for a $2 payoff, your payoff would be $100 / 2 = 50 x 8 = $400. which has incorporated into it your wagered amount.
If you bet more than one horse to Win in the race, and your total wagers come to $100.... you will only get money paid on the ticket that has the winning horse number on it. The others are losers.
NOW .. if you are asking if you get your original bill that you made the wager with handed back to you when you cash the winning ticket....( because it has a lucky Serial Number on it for example ) MOST LIKELY NOT.