Answer:
85 Passengers (20 plus additional 65) will result in maximum revenue for the owner of the yacht. Maximum Revenue will be $28,900.
Explanation:
current: 20 passengers at $600 each
let the number of additional passengers be x
cost per passenger = 600 - 4x
revenue (R) = (20+x)(600-4x)
= 12000 - 80x + 600x -4 x^2
dR/dx = -80 + 600 - 8x = 0 for a max of R
8x = 520
x = 65
There should be an additional 65 or a total of 85 passengers
The cost per passenger would be 600-4(65) or $340 per day
Maximum revenue for the yacht:
revenue (R) = (20+x)(600-4x)
revenue (R) = (20+65)(600-4(65))
revenue (R) = (85)(600-260)
revenue (R) = $28,900