Question 364896
Marie jogs at an average speed of 6 miles per hr for 1.5 hrs along a straight
 path and then turns around to jog back to her starting point.
Marie had scheduled 2.5 hrs to jog the total distance.
If Marie is to arrive back exactly on scheduled, at what average speed, in miles
 per hrs, must she jog back to her starting point?
:
Find the distance to the point he turns around.
1.5 * 6 = 9 mi
This is also the distance to the starting point
2.5 - 1.5 = 1 hr is the time required to return to the starting point
It's obvious he has to jog at 9 mph, to go 9 mi in 1hr
:
Confirm this with a time equation
Write a time equation: time = dist/speed
{{{9/6}}} + {{{9/9}}} = 2.5
1.5 + 1 = 2.5