Let's break the problem down:

• The first 3 hours cost $4.00.
• After the first 3 hours, Ted is charged $1.50 for each additional half hour.
• Ted has $11.50 in total.

To find out how long Ted can park, we need to determine how many additional hours he can afford after the initial 3 hours.

Step 1: Calculate the remaining money after the first 3 hours

Ted pays $4.00 for the first 3 hours. So, the remaining money is: $11.50 - 4.00 = 7.50$

Step 2: Determine how many half-hour blocks Ted can afford

Each additional half hour costs $1.50. The number of half-hour blocks Ted can afford is: $\frac{7.50}{1.50} = 5 \text{ half-hour blocks}$

Step 3: Convert the half-hour blocks to hours

Since 5 half-hour blocks equal $\frac{5}{2} = 2.5$ hours, Ted can afford an additional 2.5 hours.

Step 4: Calculate the total parking time

Ted can park for the initial 3 hours, plus the additional 2.5 hours: $3 + 2.5 = 5.5 \text{ hours}$

Thus, Ted can park for 5.5 hours with his $11.50.

Would you like more details or have any questions?

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Here are 5 related questions to expand your understanding:

1. How much would Ted pay if he parked for 7 hours?
2. What would be the maximum parking time if Ted had $20?
3. How much more money would Ted need to park for 6 hours?
4. If the cost per additional half hour increased to $2.00, how long could Ted park with $11.50?
5. How would the total time change if the first 3 hours cost $5.00 instead?

Tip: Always calculate the base cost first and then the incremental costs when dealing with tiered pricing systems like this one.