Probability Review

An unprepared student takes a 3-question true/false quiz in which he guesses the answers to all 3 questions. What is the probability he gets all 3 correct?

• 1/2

• 1/3

• 1/6

• 1/8

You give the answer to a probability problem as 6/5. The teacher marks it wrong. Why?

• It should have been 5/6.

• Its not written as a percent.

• Its more than 1.

• Its not written as a decimal.

Roll a die one time. Find P(rolling a 4).

• 1/4

• 2/3

• 1/6

• 1/2

Roll a die one time. Find P(even number).

• 1/2

• 1/3

• 3/6

• 2/6

Draw one card from a standard deck. Find P(ace)

• 1/13

• 1/4

• 4/13

• 1/52

There are 10 counters in a bag, 3 red and 7 blue.

I take one counter, then another without replacement.

Find the probability of picking two red counters.

• ⁶/₉₀

• ⁵/₁₉

• ⁴⁷/₉₀

• ²/₉

Bert & Ernie choose a juice to have for breakfast.

The probability that Bert chooses orange is ³/₄.

If Bert chooses orange, the probability that Ernie chooses orange is ⁴/₅.

If Bert chooses apple the probability that Ernie chooses apple is ²/₃.

Find the value of the probability marked c.

• ¹/₄

• ¹/₅

• ¹/₃

• ³/₄

Two dice are rolled and it is recorded whether the result on each is odd or even. What is the probability that one is even and one is odd?

• 1/2

• 1/4

• 3/4

• 1/3

Two dice are rolled and it is recorded whether the result on each is odd or even. What is the probability both are odd?

• 1/4

• 1/2

• 2/4

• 3/4

The tree diagram shows the outcomes of rolling a die and flipping a coin.  
How many total outcomes are there?  

• 6
• 12
• 24
• 36