Chapter 13.5, Problem 13PPS

To determine

To determine probability that the first and second buttons given away are both red.

Answer to Problem 13PPS

Probability is $\frac{20}{161}.$

Explanation of Solution

Given information:

  

Total number of amount of button = 20+15+25+10=70

Now the probability that the first give away is red is $\frac{25}{70}=\frac{5}{14}$

Now the probability that another give away is red is $\frac{24}{69}$

(This is because one red button is already given, there are total 59 button left and 24 red button left)

Probability that both given away are red is,

  $P=\frac{5}{14}\cdot \frac{24}{69}=\frac{20}{161}$