One counter is taken at random from the bag and one counter is taken at random from the box. Complete the tree diagram and work out the probability of selecting two red counters.

The Venn diagram shows there are \(29 + 22 = 51\) pupils who own exactly one device (this becomes the denominator of the conditional probability). Out of these 51 pupils, 29 own a laptop.

A tree diagram is helpful for working with event intersections and conditional probabilities ... Example: Lizard Color Preference Use the tree to find the probability that a randomly selected capture ...