9709 P52 - Jun 2021 - Q3
2587
On each day that Alexa goes to work, the probabilities that she travels by bus, by train or by car are 0.4, 0.35 and 0.25 respectively. When she travels by bus, the probability that she arrives late is 0.55. When she travels by train, the probability that she arrives late is 0.7. When she travels by car, the probability that she arrives late is x.
On a randomly chosen day when Alexa goes to work, the probability that she does not arrive late is 0.48.
(a) Find the value of x.
(b) Find the probability that Alexa travels to work by train given that she arrives late.
