Ken is comparing the cost of two different food-delivery apps. The total amount the apps charge depends on how far Ken's home is from the restaurant. One app charges $0.50 per mile, plus a $3 service fee. The other charges $0.75 per mile, with no additional fee.

How far from Ken's home would a restaurant need to be for the two options to cost the same?
Simplify any fractions.
miles

1 answer

Let \( d \) be the distance in miles from Ken's home to the restaurant. We can set up equations for the total cost for each app:

For the first app: \[ \text{Cost}_1 = 0.50d + 3 \]

For the second app: \[ \text{Cost}_2 = 0.75d \]

We want to find the distance \( d \) such that the costs of both apps are equal: \[ 0.50d + 3 = 0.75d \]

Next, we can solve for \( d \). First, we can subtract \( 0.50d \) from both sides: \[ 3 = 0.75d - 0.50d \] \[ 3 = 0.25d \]

Now, divide both sides by \( 0.25 \): \[ d = \frac{3}{0.25} \]

Calculating this gives: \[ d = 3 \div 0.25 = 3 \times 4 = 12 \]

Thus, the distance from Ken's home to the restaurant for both apps to cost the same is \( \boxed{12} \) miles.