I'm not sure how to get speed using what they've given me.

d = Distance traveled in 1 portion of trip
2d = Total Distance Traveled
S1 = 59.5
Savg = 30.5

What you need is S2

Average speed = Total Distance / Total Time

Total time can be represented as: (d/S1) + (d/S2)

Plugging into the bolded equation

Savg = 2d / ( (d/S1) + (d/S2) )

This equation simplifies to

Savg = (2*S1*S2) / (S1 + S2)

Now it's just basic algebra

S2 = 20.506 mi/hr

Okay everything you said makes perfect sense thanks for clearing it up. I'm not really sure how you used algebra to solve that, maybe I need to get more sleep .

Will toss you a bit of fg if you explain how you solved that

This post was edited by KitsuneYosh on Jan 26 2015 09:35am

so he had Savg = 2d / ( (d/S1) + (d/S2) )
get comon denominator with ( (d/S1) + (d/S2) )
givin (dS2 + dS1)/ (S1S2)
=d(S2 + S1)/(S1S2)
now u have 2d / d(S2 + S1)/(S1S2)
=2d(S1S2) / d(S2+S1)
=2(S1S2) / (S2+S1)

Hehe I don't really get it at all You lost me at that step I don't know how you went from what he had to that

Sent you some fg anyway

Which step are you getting lost?