I am having trouble with the following problem, your help is greatly appreciated.

Super Cola sales breakdown as 80% regular soda and 20% diet soda. While 60% of the regular soda is purchased by men, only 30% of the diet soda is. If a woman purchases Super Cola, what is the probability that it is a diet soda? (Hint: The 60% and 30% values are conditional probabilities stated as percentages.)