AP ICET 2017

Question 150

Three balls are drawn at random from a box contaming 9 red and 6 white balls. The probability that one ball drawnis red and the others are white is

Solution

The ways in which this can happen when we pick a ball at a time from the sack is:
RWW, WRW, WWR 

The probability of the first case = (9/15)*(6/14)*(5/13) = 9/91
Similarly, the probability of the second and third cases will also be equal to 9/91

Hence, the final probability for the desired result = 3*(9/91) = 27/91


Create a FREE account and get:

  • Download Maths Shortcuts PDF
  • Get 300+ previous papers with solutions PDF
  • 500+ Online Tests for Free

cracku

Boost your Prep!

Download App