DATA ANALYSIS QUIZ #11 : Conditional Probability

GRE Quant Problem Solving
1

image
image954×206 9.37 KB

The above is the solution:

Doubt: Where am I going wrong:

  1. Probability of rolling at atleast one “4” = 1 - (probability of rolling All not 4 ) = 1 - (5/6)^(4) = (671 /1296)
  2. Probability of 4 is not rolled exact 3 times = configuration will be = (4)-(not 4)-(not 4)-(not 4) = [ (1/6) * (5/6)^(3) ] x 4 = (500 / 1296)

Required probability = diving 2 and 1 = 500 / 671

Please help

2

What do you think this means?

3

What I think is:
when I rolled the dice 4 times, I want exactly three numbers which are not 4 = three not 4’s

and one 4

so configuration is (4) (not4) (not4) (not4)

4

Indeed, the question was ambiguous. This has been fixed, so you’re right.

1 Like
5

Thank! a Tonn

This question was indeed disturbing me