SOLUTION: An athlete runs up a set of stadium stairs at a rate of 2 stairs a second, turns around and descends those same stairs at a rate of 3 stairs per second. If the workout takes 90 sec

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: An athlete runs up a set of stadium stairs at a rate of 2 stairs a second, turns around and descends those same stairs at a rate of 3 stairs per second. If the workout takes 90 sec      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 1018280: An athlete runs up a set of stadium stairs at a rate of 2 stairs a second, turns around and descends those same stairs at a rate of 3 stairs per second. If the workout takes 90 seconds, how long does it take him to run UP the stairs.
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
RT=D travel rates rule
Time is seconds, distance in steps
             rate      time(seconds)      distance(how many steps)
UP           2          d/2                  d
DOWN         3          d/3                  d
TOTAL                    90

d%2F2%2Bd%2F3=90

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

An athlete runs up a set of stadium stairs at a rate of 2 stairs a second, turns around and descends those same stairs at a rate of 3 stairs per second. If the workout takes 90 seconds, how long does it take him to run UP the stairs.
Let time taken to run up the stairs be T
Then time it takes him to run down = 90 - T
The distance equation is thus formed: 2T+=+3%2890+-+T%29
2T = 270 - 3T
2T + 3T = 270
5T = 270
T, or time taken to run up the stairs = 270%2F5, or highlight%28highlight_green%28highlight%28matrix%281%2C2%2C54%2Cseconds%29%29%29%29