Biology: Hardy-Weinberg Principle help needed?

In an area of forest upwind from an industrial center, 500 pepper moths were trapped. Of these, 85 were dark coloured and the rest were light in colour. In a second forest sample, downwind from the industrial center, 300 moths were trapped. Of these 210 were dark colour and the rest were light.

A) Use the Hardy-Weinberg principle to calculate the frequency of the dark and light allele in the area upwind from the industrial center.

B) Do the same for the area down wind from the industrial center

C) Suggest reasons to account for these difference in allele frequencies