JohnnyGrey
New member
- Joined
- Jul 21, 2008
- Messages
- 4
Here us the problem:
Johnny walks to school at 3 miles an hour, and runs home at 5 mph. The round trip takes 1 hour. What is the distance (round trip)?
The choices given are a) 3 b) 3.12 c) 3.75 d)4 e)5
Since the distance to the school is the same as the distance back, I figured I would have to do something with 1/2d for each fo the speeds, but I am unable to come up with any of the numbers given in the choices.
This is the approach I took:
d = t/s
t = ds
(1/2d)(3) + (1/2d)(5) = 1 hour
I have also done this same equation using 60 minutes instead of 1 hour.
I can't figure out what I am doing wrong, or a different approach I should take. Does anyone know how to solve this?
Johnny walks to school at 3 miles an hour, and runs home at 5 mph. The round trip takes 1 hour. What is the distance (round trip)?
The choices given are a) 3 b) 3.12 c) 3.75 d)4 e)5
Since the distance to the school is the same as the distance back, I figured I would have to do something with 1/2d for each fo the speeds, but I am unable to come up with any of the numbers given in the choices.
This is the approach I took:
d = t/s
t = ds
(1/2d)(3) + (1/2d)(5) = 1 hour
I have also done this same equation using 60 minutes instead of 1 hour.
I can't figure out what I am doing wrong, or a different approach I should take. Does anyone know how to solve this?