SOLUTION: three balls are randomly selected without replacement from a bag containing 20 balls numbered 1, 2 through 20. if we bet that at least one of the balls has a number greater than or

Algebra ->  Probability-and-statistics -> SOLUTION: three balls are randomly selected without replacement from a bag containing 20 balls numbered 1, 2 through 20. if we bet that at least one of the balls has a number greater than or      Log On


   



Question 333173: three balls are randomly selected without replacement from a bag containing 20 balls numbered 1, 2 through 20. if we bet that at least one of the balls has a number greater than or equal to 17 what is the propability that we will win the bet
Answer by jrfrunner(365) About Me  (Show Source):
You can put this solution on YOUR website!
let x=number of balls whose number is >= 17
--
we want
in a sample without replacement
P(X>=1) = 1-P(x=0) (Getting at least one is the same as the complement of getting none)
---
P(x=0)=P(all 3 are numbered <17) =%2816%2F20%29%2A%2815%2F19%29%2A%2814%2F18%29=0.491
P(X>=1)=1-0.491=0.509
===
This could also be solved as
1-+16C3%2A4C0%2F20C3++