Question 175072
p = unit price in dollar of a rugby shirt

2000-100p = number of unit that he expect to sell

R(p) = Total revenue


R(p) = p(2000-100p)
R(p) = 2000p - 100p^2
Ans to a: R(p) = 2000p - 100p^2

For b:

R(5) = 2000x5-100x5x5
R(5) = 10000-2500
R(5) = 7500

R(10) = 2000x10-100x10x10
R(10) = 20000-10000
R(10) = 10000

R(20) = 2000x20-100x20x20
R(20) = 40000-40000
R(20) = 0