Conditional Probability

Alex took two tests. The probability of him failing both tests is 0.4. The probability of him failing the first test is 0.2. What is the probability of Alex passing the second test given that he has passed the first test?

• 0.75

• 0.25

• 0.35

• 0.15

A bag contains red and blue marbles. Two marbles are drawn without replacement. The probability of selecting a red marble and then a blue marble is 0.28. The probability of selecting a red marble on the first draw is 0.5. What is the probability of selecting a blue marble on the second draw, given that the first marble drawn was red?

• 0.75

• 0.56

• 0.65

• 0.46

A new credit card has been issued to 2000 customers. Of these customers, 1500 hold a Visa, 500 hold an AA card, and 40 hold a Visa and AA card. Find the probability that a random chosen customer holds an AA, given they hold a Visa.

• .0267

• 37.5

• .02

• .3333

What is the probability that a student does play a sport given they do not play an instrument? 

• .2
• .2222
• .10
• .5

Maya asked students about their favorite ice cream flavor. What is the probability of being a junior and liking chocolate best?

• 0.33

• 0.65

• 0.57

• 0.58

What is the probability that the person picked will be a boy given they speak german? 

• .7273
• .4
• .16
• .22

Consider the following table with information about all of the students taking Statistics at Happy High School.

Find P(Part Time given Female) =

• 15/31

• 43/71

• 31/43

• 15/43

In a class of students, the following data table summarizes how many students have a brother or a sister. What is the probability that a student has a brother given that they do not have a sister? Write your answer as a fraction

What percentage of males drive sports cars?

• 35%
• 16.25%
• 65%
• 25%

What is P(Foreign language | Sport)?

• 14/27
• 7/12
• 23/47
• 37/47