Answer:
The revenue of the company will be maximum when the price of each phone will be $60.
Step-by-step explanation:
The company charges $80 per phone and sells 800 phones each week .
Now, if the price of each phone is reduced by $2 then it sells 40 more phones per week.
Therefore, for $2x decrease in price the number of phones sold per week will be (800 + 40x)
Therefore, the revenue of the company will be given by the function
R(x) = (800 + 40x)(80 - 2x)
R(x) = 64000 - 1600x + 3200x - 80x²
R(x) = 64000 + 1600x - 80x² ............ (1)
The condition for maximum revenue is R'(x) = 0
So, differentiating equation (1) with respect to x we get
R'(x) = 1600 - 160x = 0
⇒ x = 10
Therefore, the revenue of the company will be maximum when the price of each phone will be $(80 - 10 × 2) = $60 (Answer)