Answer:
The total distance of the round trip was 4 miles
Step-by-step explanation:
1. Let's check all the information given to answer the question correctly:
Speed of Dave walking to his friend's house = 4 mph
Speed of Dave biking from his friend's house = 10 mph
Time walking is 18 minutes longer than time biking
2. What was the total distance of the round trip?
Time walking = x
Time biking = x - 18
For solving x, we will use the following equation:
4x = 10 * (x - 18)
4x = 10x - 180
-6x = - 180
x = -180/-6 (Dividing by - 6)
x = 30
Dave walked 30 minutes and biked 12 minutes, now we can calculate the total distance, this way:
30 minutes = 0.5 hours and 12 minutes = 0.2 hours
Total distance = 4 *0.5 + 10 * 0.2
Total distance = 2 + 2
Total distance = 4 miles.