Get premium membership and access revision papers with marking schemes, video lessons and live classes.

Processing. Please wait.

Mr. Karanja owns a bicycle which he sometimes rides to go to work. Out of the 21 working days in a month, he only rides to work for 18 days. If he rides to work, the probability that he is bitten by a rabid dog is
`4/15` otherwise its only `1/13`. When he is bitten by the dog, the probability that he will get treatment is `4/5` and if he does not get treatment the probability that he will get rabies is `5/7`.
(a) Draw a tree diagram to show the events
(b) Using the tree diagram in (a) above, determine the probability that
(i) Karanja will not be bitten by a rabid dog
(ii) He will get rabies
(iii) He will not get rabies if he does not get treatment