# Unit Quiz: Probability 3 (Tree diagrams)

Close

## Q1.Here is the first branch of a probability tree diagram. 1. A
2. B
3. C
4. D

1. A

## Q2.Here is the first branch of a different probability tree diagram. What should the missing probability be? 1. 0.82
2. 0.41
3. 0.18
4. 18

1. 0.18

## Q3.This tree diagram shows Amir taking red and blue counters from a jar. He replaces the counter after he has picked one up. 1. A
2. B
3. C
4. D

1. C

## Q4.For the probability tree shown, which calculation will find the probability of red followed by blue happening? 1. 0.2 x 0.2
2. 0.2 x 0.8
3. 0.2 + 0.2
4. 0.8 x 0.8

1. 0.2 x 0.8

## Q5.The probability that Amy and Joe win a game of chess is shown in the tree diagram. Work out the probability that over 2 games Amy wins twice. 1. 0.09
2. 0.6
3. 0.9
4. 0.49

1. 0.09

## Q6.James draws this probability tree diagram to help him calculate probabilities of taking sweets from a bag. What assumptions has James made when completing this probability tree? ### Options:

1. All probabilities add to 1 on each branch.
2. He replaces the first sweet he takes.
3. It doesn’t matter if he eats the first sweet he takes.

1. He replaces the first sweet he takes.

## Q7.Amy is going to pick 2 biscuits from a box. Some are chocolate and some are plain. The probability tree shows the probability information. 1. A
2. B
3. C
4. D

1. A

## Q8.James is also going to pick 2 biscuits from a box. Some are chocolate and some are plain. The probability tree shows the probability information. 1. A
2. B
3. C
4. D

1. C

## Q9.Here is a probability tree showing Amir taking red and blue sweets from a bag. 1. P(R,R)
2. P(R,B)
3. P(B,R)
4. P(B,B)

1. P(B,R)

## Q10.Probability of a dependent event is also called?

### Options:

1. Conditional probability.
2. Biased probability.
3. Random probability.
4. Mutually exclusive.

1. Conditional probability.

## Q11.Simon has drawn this probability tree for a question on dependent probability. What mistake has he made? ### Options:

1. The fractions on each branch do not sum to 1.
2. The second part of the probability tree has incorrect probabilities.
3. The probabilities should be decimals.

1. The second part of the probability tree has incorrect probabilities.

## Q12.This tree diagram shows Amir taking red and blue sweets from a bag. He does not replace the sweet after he has taken one. 1. A
2. B
3. C
4. D