Two cars travel in the same direction along a straight highway, one at a constant speed of 55 mi/h and the other at 70 mi/h.
(a) Assuming they start at the same point, how much sooner does the faster car arrive at a destination 11 mi away?
_________min
(b) How far must the faster car travel before it has a 15-min lead on the slower car?
_________mi