# help

• Jan 21st 2007, 05:07 PM
zasi
help
a migrating elephant herd started moving at the rate of 6 miles per hour. one elephant stood still and was left behind.then this stray elephant sensed danger and began running at the rate of 10 miles per hour to reach the herd. the stray caught up in 5 minutes.
1. how long (in hours) did the stray run to catch up?how far did it run?
2. find the distance that the herd traveled while the stray ran to cacth up.let x represent the distance that the herd traveled while the stray elephant stood still.
• Jan 21st 2007, 07:22 PM
CaptainBlack
Quote:

Originally Posted by zasi
a migrating elephant herd started moving at the rate of 6 miles per hour. one elephant stood still and was left behind.then this stray elephant sensed danger and began running at the rate of 10 miles per hour to reach the herd. the stray caught up in 5 minutes.
1. how long (in hours) did the stray run to catch up?how far did it run?

The stray elephant ran for 5 minutes, which is 5/60=1/12 hour.

In 1/12 hour at 10 miles per hour the elephant ran 10/12=5/6 miles

Quote:

2. find the distance that the herd traveled while the stray ran to cacth up.let x represent the distance that the herd traveled while the stray elephant stood still.
The herd was travelling at 6 miles per hour, so in the 1/12 hour the stray
was running it travelled 6/12=1/2 mile.

The distance the herd travelled while the stray stood still x=5/6-1/2=1/3 mile.
So the time that the stray stood still was the time it took the herd to
travel 1/3 mile at 6 miles per hour, which is (1/3)/6=1/18 hour=3 1/3 minutes
or 3 min 20s.

RonL