Suppose that a machine filling bottles of paediatric liquid paracetamol fills the bottles so that the mean volume of the bottles is 250ml with a standard deviations of 20ml.

If a bottle is selected at random what is the probability that:

i) the volume of the bottle will be less than 230ml;

ii) the volume of the bottle will be between 230ml and 260ml;

iii) more than 230ml?