A Broadway theater offers 3 tickets per performance at 70% discounted price by drawing random lottery to the people waiting in a line before the show. Today, 10 people are waiting in a line to win a lottery.
Now, the theater grants 3 different discount prices for 3 winners; 100% off for the 1st winner, 75% off for the 2nd winner,and 20% off for the 3rd winner. How many ways exist to have 3 lottery-winners among 10 people on a line?