Answer to Question #148568 in Statistics and Probability for poop

Question

A box contains 40 Balls, 25% of them are white whereas the rest of them are black. A person randomly
picked 4 balls from the box without replacement, find the probability of getting 3 black balls and 1
white ball.

Answer 1

Given:

Total= 40

Number of white balls: 25% *40= 10

Number of black= 40-10=30

Without replacement:

P(3 black balls and 1 white ball)= $\frac{30}{40}* \frac{29}{39}*\frac{28}{38}*\frac{10}{37}$

=$\frac{243600}{21,93,360}$

=0.111