On any day, Kino travels to school by bus, by car or on foot with probabilities 0.2, 0.1 and 0.7 respectively. The probability that he is late when he travels by bus is \(x\). The probability that he is late when he travels by car is \(2x\) and the probability that he is late when he travels on foot is 0.25.
The probability that, on a randomly chosen day, Kino is late is 0.235.
(a) Find the value of \(x\).
(b) Find the probability that, on a randomly chosen day, Kino travels to school by car given that he is not late.
Maria chooses toast for her breakfast with probability 0.85. If she does not choose toast then she has a bread roll. If she chooses toast then the probability that she will have jam on it is 0.8. If she has a bread roll then the probability that she will have jam on it is 0.4.
(i) Draw a fully labelled tree diagram to show this information.
(ii) Given that Maria did not have jam for breakfast, find the probability that she had toast.
A box contains 4 pears and 7 oranges. Three fruits are taken out at random and eaten. Find the probability that
At a zoo, rides are offered on elephants, camels and jungle tractors. Ravi has money for only one ride. To decide which ride to choose, he tosses a fair coin twice. If he gets 2 heads he will go on the elephant ride, if he gets 2 tails he will go on the camel ride and if he gets 1 of each he will go on the jungle tractor ride.
(i) Find the probabilities that he goes on each of the three rides.
The probabilities that Ravi is frightened on each of the rides are as follows:
elephant ride \(\frac{6}{10}\), camel ride \(\frac{7}{10}\), jungle tractor ride \(\frac{8}{10}\).
(ii) Draw a fully labelled tree diagram showing the rides that Ravi could take and whether or not he is frightened.
Ravi goes on a ride.
(iii) Find the probability that he is frightened.
(iv) Given that Ravi is not frightened, find the probability that he went on the camel ride.
There are three sets of traffic lights on Karinneโs journey to work. The independent probabilities that Karinne has to stop at the first, second and third set of lights are 0.4, 0.8 and 0.3 respectively.