Explain every part All created functions mu st have units Se
Solution
a) Cost = fixed cost + variable cost
Let m be the number of members
Fixed costs = 11,000 Variable costs = 35 per member = 35 * m
Hence cost function C(m) = 11000+35m ...............(1)
b)Since the demand function is linear, we know that it can be written in slope-intercept form as
p = am+b where p is the price per member
When m=1000, p = 100: 100 = 1000a + b ..........(i)
When m =1800, p = 60: 60 = 1800a + b ..............(ii)
Subtracting equation (ii) from (i) we get, 40= -800a this gives a = -40/800= -0.05
Substituting a = -0.05 in equation (i) we get 100 = 1000(-0.05)+b which implies 100= -50 +b
Therefore b = 100+50 = 150. Hence the demand function is p = -0.05m + 150........(2)
c) we need to find p for m = 0. Substitute m =0 in eqn(2)
p = 150 Hence there will be no members for monthly price 150 per member
d) The revenue function is found by observing that revenue = price x quantity
Since we are looking for revenue as a function of the quantity m,we’ll rewrite this as R(m)= pm
R(m) = (-0.05m+150)m = -0.05m2+150m
e) profit = Revenue-cost
P(m) = R(m) - C(m)= -0.05m2+150m - (11000+35m)
P(m)= -0.05m2+115m - 11000
f) For no members m = 0
P(0) = -11000
Hence for no members there will be a loss of $11,000
g) for break even point C(m) = R(m)
11000 + 35m = -0.05m2+150m
-0.05m2+115m - 11000=0
Dividing through out by -0.05 we get
m2 - 2300m + 220000 = 0
m2- 2200m - 100m + 220000= 0
Factoring we get
(m-2200)(m-100) = 0
Which means m=100 or m= 2200
So the club will break even for the first 100 members.
h) for profit we need to solve
P(m) > 0 which implies -0.05m2+115m - 11000 > 0 i.e. 100<m<2200
P(100) = -0.05(100)+150 = 145; P(2200)= -0.05(2200)+150= 40
Hence for Profits price per member is between 40 and 145
i) For maximum profit we look at the axis of symmetry of the above quadratic equation
m =-b/2a = -115/2(-0.05)=1150. So 1150 members will maximize profit
k) Cost per member for maximum profit= -0.05(1150)+150 = $92.5
j) P(1150) = 55,125 Hence max profit = $55,125

