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An airport limo service charges riders a fixed charge of $20 plus $3.00 per mile. How many miles must a rider go to have an average cost per mile of $3.80?

A) 5 miles
B) 6 miles
C) 8 miles
D) 10 miles

1 Answer

4 votes

Final answer:

To find the number of miles required to make the average cost per mile $3.80 for a limo service with a $20 fixed charge plus $3 per mile, set up a linear equation. Solving this, the number of miles comes out to be 25, which is not an option given in the question indicating a probable discrepancy in the provided information.

Step-by-step explanation:

The student is asking about a linear equation problem involving an airport limo service with a fixed charge and a per mile charge. To find the number of miles that makes the average cost per mile equal to $3.80, we can set up the equation:

Let the number of miles be x. The total cost is the fixed charge plus the cost per mile times the number of miles, which is $20 + $3x. The average cost per mile will be this total cost divided by the number of miles, or ($20 + $3x) / x.

We want the average cost to be $3.80, so we set the equation
($20 + $3x) / x = $3.80

Multiplying both sides by x to clear the fraction gives:
$20 + $3x = $3.80x

Moving terms involving x to one side, we have:
$3.80x - $3x = $20

That simplifies to:
$0.80x = $20

Now, dividing both sides by $0.80 gives:
$x = $20 / $0.80

Which yields:
$x = 25 miles

However, this number of miles is not found in the options provided (A) 5 miles, (B) 6 miles, (C) 8 miles, (D) 10 miles, so it seems there has been a mistake in the calculations or in the options provided. The student should verify the options or redo the calculations.

User Rajesh Patel
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