- Thread starter Cook$
- Start date

you state you go 'out' for a run and do 10 miles per hour on the way 'out'

once you are 'out' you are already on your way back so do your run entirely at 12 miles per hour

or if its not a trick question and assuming that by 'out' and 'back' you are referring to running to and from a fixed point returning to the same start point then 11 miles per hour

10mph and 12mph, or 22 mp 2h

Divide by 2 hours = 11mph

(Note is 'per hour' not 'in an hour', only 10 miles are run back, in less than an hour - but the actual time and distance are still irrelevant)

10 mph is the same as 10 mp 60mins

12 mph is the same as 12 mp 60mins

1 mp 6 mins, 1 mp 5 mins

2 mp 11 mins = 10 mp 55 mins

We need to add 5 minutes for 'per hour'

1 mile would be 5.5 mins (or 5:30)

Shocker - it's not 11mph but 10 point something

Lets chuck some numbers in. Say I run 10 miles out, at 10mph. Thats 10 mile in 60 mins, 6 min miles

Then back at 12mph. So 10 mile at 12mph gives 5 min miles. So 50 mins.

60mins + 50 mins =110mins

Ran 20 miles in 110 mins

S = d/t = 20/110 = 0.1818 miles per min

x 60 = 10.9mph

Lets chuck some numbers in. Say I run 10 miles out, at 10mph. Thats 10 mile in 60 mins, 6 min miles

Then back at 12mph. So 10 mile at 12mph gives 5 min miles. So 50 mins.

60mins + 50 mins =110mins

Ran 20 miles in 110 mins

S = d/t = 20/110 = 0.1818 miles per min

x 60 = 10.9mph

This sounds legit to me

Yep, since you were running slower for longer your average speed will be less than 11mph

Lets chuck some numbers in. Say I run 10 miles out, at 10mph. Thats 10 mile in 60 mins, 6 min miles

Then back at 12mph. So 10 mile at 12mph gives 5 min miles. So 50 mins.

60mins + 50 mins =110mins

Ran 20 miles in 110 mins

S = d/t = 20/110 = 0.1818 miles per min

x 60 = 10.9mph

Nice little brain bender