Johnny's home is m miles from school. Johnny runs to school at a speed of 8 mph and then walks home from school at half that speed. How much longer does it take Johnny to walk home than to run to school?

Answer 1

To run to school, Johnny travels m/8 miles, which takes m/8 / (8 m/h) = 1/64 h = 1.5 minutes.

To walk home, Johnny travels m/16 miles, which takes m/16 / (4 m/h) = 1/64 h = 1.5 minutes.

Thus, Johnny takes 1.5 - 1.5 = <<1.5-1.5=0>>0 minutes longer to walk home than to run to school. Answer: \boxed{0}.