A breathalyser test is used by police in an area to determine whether a driver has an excess of alcohol in their blood.

The device is not totally reliable: 8 % of drivers who have not consumed an excess of alcohol give a reading from the breathalyser as being above the legal limit, while 10 % of drivers who are above the legal limit will give a reading below that level.
Suppose that in fact 15 % of drivers are above the legal alcohol limit, and the police stop a driver at random.
Give answers to the following to four decimal places.

1 answer

What following?