Given, a parking lot charges $3 for first hour and $2 per hour after that.
So for t hours, the parking lot charges $3 for the first hour and after first hour there is hours left.
So for hours it will charge $2 per hour.
The charges for hours = $
.
Total charges for t hours for one car = $
Now for the second car, it will charge 75% of the first car.
So the charges for second car
=$[ ]
=$
There are 3 cars. That parking charges for the third car is also 75% of the first car.
So for third car the parking charges are same as for the second car.
Total parking charges for 3 cars
= $
= $
We have got the required answer here.
The correct option is option C.