Conditional Probability Review

Jim and Sue each take a driving test.

The probability that Sue will pass the driving test is 0.6

What is the probability he fails the test?

(a)  

Find the probability that Terri takes one pen of each colour from the box?

(Give answer as a fraction)

(a)  

A fruit basket contains 9 apples, 3 bananas, 7 oranges, 5 pears, and 1 grapefruit. Stanley randomly chooses a fruit, does not replace it, then chooses another. What is the probably that he choses two pears?

• ¹/₃₀

• ⁴/₁₂₅

• ¹/₁₀

• ⁹/₄₉

A quiz contains 5 true or false questions. If you guess on every question, what is the probability of getting all 5 questions correct?

• ¹/₆₀

• ¹/₃₂

• ¹/₂

• ¹/₁₀

A bag contains 5 quarters, 2 dimes, and 4 pennies. What is the probability of picking a quarter, not replacing it, and then picking a penny?

• ²⁰/₁₂₁

• ⁸/₁₂₁

• ²/₁₁

• ⁴/₅₅

What is the probability when Sue will randomly select from a treat bag containing 6 lollipops and 4 gum balls. Sue will select a treat, not replace it, and then select a second treat. Find P(gumball then lollipop)

There are seven nickels and six dimes in your pocket. You randomly pick a coin out of your pocket and place it on a counter. Then you randomly pick another coin. What is the probability the first coin is a nickel and the second coin is a dime?

There are six nickels and seven dimes in your pocket. You randomly pick a coin out of your pocket and then return it to your pocket. Then you randomly pick another coin. What is the probability both times the coin is a nickel?

A basket contains four apples and six

peaches. You randomly select one piece

of fruit and eat it. Then you randomly

select another piece of fruit. What is the probability both pieces

of fruit are apples?

• 1 / 17 = 0.059

• 2 / 15 = 0.133

• 1 / 4 = 0.25

• 25 / 169 = 0.148

A marble bag contains 3 red marbles, 4 gray marbles, 6 white marbles, and 5 black marbles. What is the probability of randomly drawing a red marble and then a gray marble if the first marble is replaced?

• 1/9

• 1/27

• 1/6

• 2/9