Mathematics 4024 · O Level · Probability of combined events

Probability of combined events — practice question

The bag contains $9$ red counters and $3$ green counters. Lee selects two counters at random from the bag, without replacement.
(a)[2]

Complete the tree diagram.

(b)[1]

Calculate the probability that both counters are red.

Worked solution & mark scheme

This 3-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Tree diagram with the probabilities shown correctly” …

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI