Jerry can run from his house to his school and back in the time it takes his brother Carson to run to the school. If it takes Jerry 15 minutes to make a one-way trip from his house to his school and the school is 4 miles away, how fast does Carson run in miles per hour? Let's answer step by step:
We know that Carson takes twice as long as Jerry to get to the school, so we can find the time it takes him by multiplying Jerry's time by 2: 15 minutes * 2 = 30 minutes. Then convert that time to house by dividing by 60 minutes / hour = 30 minutes / 60 minutes / hour = .5 hour. Then divide the distance Carson runs by the time it takes him to run it to find his speed: 4 miles / 0.5 hours = 8 miles / hour. The answer: 8.