A parking lot charges $3 to park a car for the first hour and $2 per hour after that. If you use more than one parking space, the second and each subsequent car will be charged 75% of what you pay to park just one car. If you park 3 cars for t hours, which function gives the total parking charge?

Answer 1

If you park n cars for t hours,
car 1: x = 3 + 2(t-1)
others: 3/4 that amount, or 3/4 (n-1)*x

So, the total amount will be

f(n,t) = (3+2(t-1))(1 + (3/4)(n-1))
= (3n+1)(2t+1)/4

So, 3 cars for t hours is
f(3,t) = 5/2 (2t+1)

So, let's check, say, f(3,4)=45/2=$22.50

1st car: 3 + 2*3 = 9
other 2 cars: each 3/4 of that amount, or 2*27/4 = $13.50
Total: $22.50

Answer 2

A parking lot charges a flat rate of x dollars for any amount of time up to two hours, and x
6
1
for
each hour or fraction of an hour after the first two hours. How much does it cost to park for 5 hours
and 15 minutes?