Conditional Probability Pre-Test

1. In the drawing, six out of every 10 tickets are winning tickets. Of the winning tickets, one out of every three awards a larger prize.

What is the probability that a randomly chosen ticket will award a larger prize?

A. [tex]\frac{2}{15}[/tex]
B. [tex]\frac{1}{5}[/tex]
C. [tex]\frac{5}{9}[/tex]
D. [tex]\frac{5}{6}[/tex]



Answer :

In the given problem, we need to find the probability that a randomly chosen ticket will award a larger prize.

Let's break down the problem step-by-step:

1. Determine the probability of picking a winning ticket:
- We know that six out of every ten tickets are winning tickets.
- Thus, the probability of picking a winning ticket is:
[tex]\[ P(\text{winning ticket}) = \frac{6}{10} = 0.6 \][/tex]

2. Determine the probability of getting a larger prize given that the ticket is winning:
- We are given that one out of every three winning tickets awards a larger prize.
- Thus, the probability of getting a larger prize given that the ticket is winning is:
[tex]\[ P(\text{larger prize} \mid \text{winning ticket}) = \frac{1}{3} \approx 0.333 \][/tex]

3. Calculate the overall probability of getting a larger prize:
- We are asked to find the probability that a randomly chosen ticket will award a larger prize. This can be found using the chain rule of conditional probability:
[tex]\[ P(\text{larger prize}) = P(\text{winning ticket}) \times P(\text{larger prize} \mid \text{winning ticket}) \][/tex]

4. Substitute the values into the formula:
- Using the values from step 1 and step 2:
[tex]\[ P(\text{larger prize}) = 0.6 \times 0.333 \approx 0.2 \][/tex]

So, the probability that a randomly chosen ticket will award a larger prize is approximately [tex]\(0.2\)[/tex]. In fraction form, this is:

[tex]\[ \frac{1}{5} = 0.2 \][/tex]

Therefore, the correct answer is:

[tex]\[ \boxed{\frac{1}{5}} \][/tex]