I have analyzed this last night. I got stalled at the

"...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"

Why in terms of p only? When p = 1.25 +t? Should it not be in terms of t?

t = tax component of p.

Anyway, to start the ball rolling, here's what I started last night.

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

"Assuming... a linear relationship." So the graph is a straight line. Two points determine a straight line.

"when the selling price of a packet of 20 cigarettes is $2.5, the weekly demand in the UK is 11 million"

Using (p,q) ordered pair,

(2.5,11) ---------------------one point

"and when the selling price is $4 the weekly demand is 7.15million."

(4,7.15) ------------other point.

We can get the equation of the line by using the point-slope form. Say, we use the point (2.5,11),

(q -11) = [(11 -7.15)/(2.5 -4)](p -2.5)

q -11 = (-2.566667)(p -2.5)

q = -2.566667p -6.416667 +11<----wrong. Should be +6.416667

q = -2.566667p +6.416667 +11

q = -2.566667p +17.416667 --------the demand function. (corrected)

-----------------------------

Let's see if I can go around the confusion re the C,S,E tonight.