4400 Higher June 2005 Paper 4 Q18

EdexcelHigherOld spec6 marksTree Diagrams

18 In order to start a course, Bae has to pass a test.
He is allowed only two attempts to pass the test.

The probability that Bae will pass the test at his first attempt is \(\frac{2}{5}\).

If he fails at his first attempt, the probability that he will pass at his second attempt is \(\frac{3}{4}\).

(a) Complete the probability tree diagram.
Probability tree with headings First attempt and Second attempt; first attempt branches Pass and Fail with blank probabilities; nothing drawn for the second attempt

(3)

(b) Calculate the probability that Bae will be allowed to start the course. (3)