Random Probability Problem

Bachelier

In a box with 80 tickets, 10 people buy 10 tickets each. If there are 4 winning tickets drawn at random find the probability that
1) one person gets all 3 winning tickets
2) there are 3 different winners
3) some person gets two winners and someone else gets just one

for 1) 10 C 3 * 70 C 7

is the answer = -------------------- where C stands for chooses.
80 C 10

Thnks

tiny-tim

That's 100 tickets …

have the police been informed?