Tree Diagrams & Combined Probability (Edexcel GCSE Maths: Foundation): Exam Questions

When a biased 6-sided dice is thrown once, the probability that it will land on 6 is 0.3.

The biased dice is thrown twice.

Sophie draws this probability tree diagram.

The diagram is not correct.

Write down two things that are wrong with the probability tree diagram.

On Amelia's route to work, she drives through a set of traffic lights.
She also has to cross a bridge, which is sometimes closed to cars.

The probability that the traffic lights will be red when she reaches them is 0.4.

The probability that the bridge is closed when she reaches it is 0.1.

Complete the probability tree diagram below.

Find the probability of the traffic lights being red, and the bridge not being closed.

A fair dice with 6 faces, labelled 1 to 6, is rolled twice.

Find the probability of not rolling a 1 on either of the rolls.

Wendy goes to a fun fair.
She has one go at Hoopla.
She has one go on the Coconut shy.

The probability that she wins at Hoopla is 0.4
The probability that she wins on the Coconut shy is 0.3

Complete the probability tree diagram.

Work out the probability that Wendy wins at Hoopla and also wins on the Coconut shy.

When a biased 6-sided dice is thrown once, the probability that it will land on 4 is 0.65
The biased dice is thrown twice.

Amir draws this probability tree diagram.
The diagram is not correct.

Write down two things that are wrong with the probability tree diagram.

Priya is at a fairground where she plays different games.

She plays 1 game of hook-a-duck, and then plays 1 game of balloon darts.

The probability of her winning in hook-a-duck is 0.6.

The probability of her winning in balloon darts is 0.45.

Complete the probability tree diagram below.

Find the probability that Priya wins at least 1 game.

Tommy is selecting socks from his drawer to pack for a weekend away.
His drawer contains only black socks, or coloured socks.

Tommy has 8 pairs of black socks, and 10 pairs of coloured socks in his drawer.

He takes one pair of socks out of the drawer, notes the colour, and does not replace them.
He then takes another pair of socks out of the drawer.

Complete the probability tree diagram.

Find the probability that Tommy selects one black pair of socks, and one coloured pair of socks.

The probability of finding a "shiny" card in a pack of trading cards is 0.4.

If 3 packs are purchased, find the probability of finding at least one "shiny" card.

The probability that it will rain on a day in June is 0.2

When it rains the probability that my tennis match is cancelled is 0.7

When it does not rain, the probability that my tennis match is not cancelled is 0.95

Complete the probability tree diagram for this information.

Work out the probability that, on a day in June, it does not rain and my tennis match is cancelled.

Ding is going to play one game of snooker against each of two of his friends, Marco and Judd.

The probability tree diagram gives information about the probabilities that Ding will win or lose each of these two games.

Work out the probability that Ding will win both games.

Work out the probability that Ding will win exactly one of the games.