posted by JHONY on .
There are 3 lucky tickets among 10 lottery tickets. 3 tickets are
drawn at random. What is a probability that one ticket selected randomly
from those three is lucky?
You want WLL or LWL or LLW
each has a prob of (3/10)(7/9)(6/8) = 7/40
so prob is 3(7/40) = 21/40