hi all, am just new to this forum.. and am hope that this forum will help me out in my maths problems.actually a math question brought me here...and i really need to get a solution for that question.. wish everyone will help me out..

here is the question

when the selling price of a packet of 20 cigarettes is $2.5, the weekly demand in the UK is 11 million and when the selling price is $4 the weekly demand is 7.15million.

a) find the demand function stating q, the weekly demand in millions, in terms of p, the selling price in $, assuming that this is a linear relationship.

b) suppose that the selling price of a packet of cigarettes is made up of two elements, the sellers revenue per packet and the tax paid to the exchequer per packet . you are given that the sellers revenue is fixed at $1.25 per packet although the tax paid to the exchequer per packet can be changed. find an expression for each of the following in terms of p, the selling price in $

(1) C- the total combined weekly revenue measured in $millions.

(2) S- the total seller's weekly revenue measured in $millions.

(3) E- the total exchequer's weekly revenue measure in $millions

c) (1) suppose now that packets of 20 cigarettes are sold for $4.75 what is the resulting total exchequer's weekly revenue?

(2) if the tax per packet is increased to $4.50, find the new total exchequer's weekly revenue and comment on the result including a recommendation to the exchequer.

so i will be very thankful if someone find me the answers. thanks a lot