Answer:
10 hours
Explanation:
1. Create a chart.
miles - hours
7.5. - 0.5 (30 minutes = 0.5 hours)
150. - x (let's use a variable to represent number of hours Jimmy ran)
2. Cross multiply:
7.5(x) = 150(0.5)
7.5x. = 75
3. To isolate x, divide both sides of equation by 7.5
7.5x/7.5 = 75/7.5
4. 7.5 crosses out with itself on the left side of the equation.
5. 75/7.5 = 10
x = 10
Therefore, Jimmy ran 150 miles in ten hours.