Question 23336
Let "x" be number of days that the increasing of prices has been in effect.
Then average number os passengers will be 1000-50x.
The price paid per passenger will be 200-25x cents.
The income to the company will be:
Income = (1000-50x)(200-25x)
Domain will be 0<=x<=8 for practical purposes.
Range of income will be 0<=income<=200000 cents
as the equation relates to the problem.
Just looking at the equation without reference to
the problem the Domain and the Range would be all
real numbers.  Hope you understand the difference.
The equation is a model for the problem so has 
restricted applicable domain and range.

Cheers
Stan H.