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
To find the probability that one ticket selected randomly from the three drawn tickets is lucky, we need to determine the total number of possible outcomes and the number of favorable outcomes.
Total number of possible outcomes:
Since 3 tickets are drawn from a set of 10 tickets, the total number of possible outcomes can be calculated using the combination formula, where n is the total number of items and r is the number of items being selected:
C(n, r) = n! / (r! * (n-r)!)
In this case, n = 10 (total tickets) and r = 3 (tickets being drawn):
C(10, 3) = 10! / (3! * (10-3)!) = 120
Number of favorable outcomes:
We know that there are 3 lucky tickets among the 10 tickets. Since we are drawing 3 tickets, the number of ways to select one lucky ticket out of the three will simply be 3.
Now we can calculate the probability by dividing the number of favorable outcomes by the total number of possible outcomes:
Probability = Number of favorable outcomes / Total number of possible outcomes
Probability = 3 / 120
Probability = 1/40
Therefore, the probability that one ticket selected randomly from those three is lucky is 1/40.