Conditional Probability Tree Diagrams

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. What is the probability that Bert & Ernie choose different juices?

• ³/₂₀

• ¹/₁₂

• ¹⁴/₆₀

• ¹⁹/₆₀

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

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

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

I take one counter, then another without replacement.

Find the probability of the value marked x

• ⁷/₁₀

• ³/₁₀

• ⁶/₉

• ²/₉

There are 10 counters in a bag, 3 red and 7 blue. I take one counter, then another without replacement. Find the probability of the value marked y

• ⁷/₁₀

• ³/₁₀

• ⁶/₉

• ²/₉

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 one of each colour counters.

• ²¹/₉₀

• ⁴⁸/₉₀

• ⁴²/₉₀

• ¹⁰/₁₉

What is the chance that the dessert is brownies and has peanut butter in it?

• 0.94

• 0.58

• 0.99

• 0.95

What is the chance that the dessert is not brownies and does not have peanut butter in it?

• 0.58

• 0.42

• 0.06

• 0.05

What is the probability that the dessert is brownies or does not have peanut butter in it?

• 0.99

• 0.36

• 1.32

• 0.41

What is the probability that the dessert is brownies or does have peanut butter in it?

• 0.95

• 0.99

• 0.42

• 0.64