Question 1008903
Distance(d) equals Rate (r) times Time(t) or d=rt; r=d/t and t=d/r
Let r=rate coming down hill
Then r-0.5=rate going up hill
We can't deal in both hours and minutes, sooo:
110 minutes =110/60 or 11/6 hours

Going up the hill:
d(up)=(r-0.5)*2
d(down)=r*(11/6)
We know that d(up)=d(down)
(r-0.5)*2=r*(11/6)
2r-1=11r/6   multiply each side by 6
12r-6=11r
12r-11r=6
r=6 mph
CK
d(up)=(6-0.5)*2=(5.5)*2=11 mi
d(down)=6*(11/6)=11 mi
Hope this helps---ptaylor