Final answer:
To maximize income for the ship owners, the optimal group size on the ship excursion is 83 people.
Step-by-step explanation:
Let's model the problem:
Let the number of additional people in the group be x.
Revenue = Number of people * Price per person
Price per person = Initial price - $1 for each additional person = $66 - $1x
Revenue = (50 + x)($66 - 1x)
Expand and simplify:
Revenue = $3300 + $65x - x^2
x^2 is a parabola that opens downwards
x is a positive number since we are adding people
Therefore, the revenue is maximized at the x -coordinate of the vertex.
Vertex = -(65/−2) = 32.5
Since we cannot have half a person, we round up to 33 people.
Final answer: 50 + 33 = 83
So, the number of the persons is 83.