A batch of 350 raffle tickets contains 4 winning tickets. You buy 4 tickets. What is the probability you have no winning tickets?

b.) all winning tickets?

c.) at least 1 winning ticket?

d.) At least 1 non-winning ticket?

1 answer

No winning? 346/350*345/349*344*348*343*347

There are four ways to get at least one winning ticket:
WLLL
WWLL
WWWL
WWWW

Pr(at least one winning ticket)=sum prob of all those.