Question 1072479
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The solution by "josgarithmetic" is {{{highlight(WRONG)}}}.
Below find the correct solution.
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x, number of people <U>above 50</U>.
The total number of passengers is (x+50).
Price,  {{{30-(0.5)x}}}
Cruise Revenue,  R = {{{(x+50)*(30-(0.5)x)}}}


Roots:  {{{system(x=-50,and,x=60)}}}
The middle of these is x=5, or number of people on the cruise, 50+5 = 55.
The maximum revenue, R = (50+5)*(30-0.5*5) = R1512.5.


The solution by "josgarithmetic" is {{{highlight(WRONG)}}}.