Old charges: $2 for the first two hours + $1 per hour for each additional hour thereafter.
New charges: $4 for the first four hours + $1 per hour for each additional hour thereafter.
For the new charges to bring in additional revenue, the number of users should remain relatively stable (who use the parking slot for at least 4 hours) or the number of users should increase.
(A)
Very few people who park their cars at the hourly parking lot at the airport leave their cars for more than two hours at a time. This indicates that the vast majority of the parking slot users use these slots for a maximum of 2 hours and not more. if 'X' is the number of users who use the parking slot for only two hours, then the revenue generated under the old charges would be '$2X'. With the new charges, the revenue generated from 'X' number of parking slot users would be '$4X'. this proves that the new charges do bring additional revenue. Hence,
(A) is the right answer.(B)
Over the past several years, the cost to the airport of operating its hourly parking facilities has been greater than the revenues it has received from them. - this has no relation with whether the new charges would bring in more revenue. hence,
eliminate (B)(C)
People who leave their cars at the airport while on a trip generally park their cars in lots that charge by the day rather than by the hour. - Do people use the parking slots for the entire day or only for a few hours? Without this understanding, it will be impossible to tell whether more revenue can be brought in by changing the rate. Moreover, this option literally tells us "where people park their cars" and has no bearing on the new $4 charge plan. Hence,
eliminate (C)(D)
A significant portion of the money spent to operate the airport parking lot is spent to maintain the facilities rather than to pay the salaries of the personnel who collect the parking fees. - irrelevant to the topic of discussion. hence,
eliminate (D)(E)
The hourly parking lots at the airport have recently been expanded and are therefore rarely filled to capacity. - this does not tell us whether the revenue increases or decrease, after the implementation of the new plan. For example :Say that there are 100 frequent users of airport parking slots, who use the slot for 2 hours on average. After expansion, the airport parking can now accommodate 200 cars.
Under the old parking charges, the revenue would have been $200. under the new charge plan, $400 would have been the revenue.
But what if the number of frequent users dropped after the new plan was implemented? This would certainly signal a decrease in revenue, NOT an increase.
Since (E) leaves a lot of room for speculation, (E) is not a solid answer choice. Hence,
eliminate (E)