A hint to get started
Condition on a full tank after a fuel-type split
At a petrol station,30%of customers buy leaded petrol,60%buy unleaded petrol and the remainder buy diesel. A leaded-petrol customer has a 25%chance of filling the tank; an unleaded-petrol customer has a 20%chance; a diesel customer has a 30%chance.
(i) Draw a probability tree.
(ii) Find the probability that a car leaving does not have a full tank.
(iii) Given that it has a full tank, find the probability that it contains unleaded petrol.
CJC · Lecture · Example 8
Name the events, identify the sample space, and state which outcomes or conditions are being counted.