Browse Questions

# A bag contains 8 red and 5 white balls.Three balls are drawn at random.Find the probability that all the three balls are red

$\begin{array}{1 1}(A)\;\large\frac{48}{143}\\(B)\;\large\frac{28}{143}\\(C)\;\large\frac{18}{143}\\(D)\;\large\frac{5}{143}\end{array}$

Step 1:
Given a bag contains 8 red and 5 white balls
$\therefore$ The sample space is $S=13(8+5)$
Step 2:
All three balls are red
$P=\large\frac{8}{13}\times \frac{7}{12}\times \frac{6}{11}$
$\;\;\;=\large\frac{28}{143}$
Hence (B) is the correct answer.