SOLUTION: To be a lifeguard you must swim continuously for 500 yards doing either the front crawl or the breaststroke. You can swim the front crawl 45 yards per minute and the breaststroke

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: To be a lifeguard you must swim continuously for 500 yards doing either the front crawl or the breaststroke. You can swim the front crawl 45 yards per minute and the breaststroke       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 164823: To be a lifeguard you must swim continuously for 500 yards doing either the front crawl or the breaststroke. You can swim the front crawl 45 yards per minute and the breaststroke 35 yards per minute. It takes you 12 minutes to swim 500 yards. How long did you spend swimming the front crawl?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
To be a lifeguard you must swim continuously for 500 yards doing either the front crawl or the breaststroke.
You can swim the front crawl 45 yards per minute and the breaststroke 35 yards per minute.
It takes you 12 minutes to swim 500 yards. How long did you spend swimming the front crawl?
-------------------
Front Crawl DATA:
distance = x yrds. ; rate = 45 yrd/min ; time = d/r = x/45 minutes
----------------
Breastroke DATA:
distance = 500-x yrds; rate = 35 yrs/min ; time = d/r = (500-x)/3 minutes
--------------------
EQUATION
tiime + time = 12 minutes:
x/45 + (500-x)/35 = 12
35x + 45(500-x) = 35*45*12
-10x + 45*500 = 35*45*12
-10x = -3600
x = 360 yds. (front crawl distance)
-----------
Front crawl time = 360 yds / (45 yds/mim) = 8 minutes
=================================
Cheers,
Stan H.