SOLUTION: Russ and Janet are running. Russ runs at 7mph, Janet at 5mph. If the run has a staggered start, and Janet starts first with Russ starting 10 minutes later, how long before he catch

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Russ and Janet are running. Russ runs at 7mph, Janet at 5mph. If the run has a staggered start, and Janet starts first with Russ starting 10 minutes later, how long before he catch      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 212069: Russ and Janet are running. Russ runs at 7mph, Janet at 5mph. If the run has a staggered start, and Janet starts first with Russ starting 10 minutes later, how long before he catches up with her?
Answer by drj(1380) About Me  (Show Source):
You can put this solution on YOUR website!
Russ and Janet are running. Russ runs at 7mph, Janet at 5mph. If the run has a staggered start, and Janet starts first with Russ starting 10 minutes later, how long before he catches up with her?

Step 1. Find distance Janet travels just before Russ starts running.

(5 miles/hour) * (1 hour/60 minutes) * (10 minutes) = 5%2A10%2F60=5%2F6 miles

Step 2. You need to realize that Russ and Janet must travel the same distance when Russ catches up.

distance = velocity * time

Step 3. Russ traveled 7%2Ax where x is the time (in hours) he traveled

Step 4. Janet traveled 5%2F6%2B5%2Ax where same x is the time she traveled
Step 5. Set equations equal: Step 3 = Step 4
7%2Ax=5%2F6%2B5%2Ax
Step 6. Subtract 5x from both sides of equation in previous step.

7x-5x=5%2F6%2B5x-5x
2x=5%2F6
Step 7. Divide by 2 to solve for x

2x%2F2=5%2F%282%2A6%29

Step 8. Answer is
x=5%2F12 hour or x=5%2F12%2A60=25 minutes where 60 minutes = 1 hour


For Step-By-Step Videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra.