posted by Steve on .
An elephant herd started moving at a rate of 6 mph. One elephant stood still and was left behind. Then the stray elephant began running at a rate of 10 mph to reach the herd. The stray caught up in 5 minutes. How long (in hours) did the stray run to catch up? How far did it run?
If the stray ran 10mph for 5/60 min or 1/12 hr, then it ran 5/6 miles. We used distance = rate*time.
Find the distance that the herd traveled while the stray ran to catch up.
Ok, we know the stray ran 5/6 mi to catch them. The herd traveled 6mph * 1/12 hr or .5mi in that 5 min, so they traveled 5/6 mi - 3/6 mi = 2/6 or 1/3 mi before the stray started to run.