If there are balls numbered 1 through 40 and i randomly pick out 6 balls, what is the probability that one of the balls is a 2?
Hello, chrizzle!
If there are balls numbered 1 through 40, and i randomly pick out 6 balls,
what is the probability that one of the balls is the "2"?
There are: .$\displaystyle {40\choose6} \:=\:3,\!838,\!380$ possible outcomes.
We want the "2" and 5 of the other 39 balls: .$\displaystyle {39\choose5} \:=\:575,\!757$ ways.
Therefore: .$\displaystyle P(\text{6 balls, including the "2'}) \;=\;\frac{575,\!757}{3,\!838,\!380} \;=\;\frac{3}{20}$