SOLUTION: eric plans to compete in a triathlon. he can average 2 miles per hour in the 1/4-mile swim and 6 miles per hour in the 3-mile run. his goal is to finish the triathlon in 2 hours. t

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: eric plans to compete in a triathlon. he can average 2 miles per hour in the 1/4-mile swim and 6 miles per hour in the 3-mile run. his goal is to finish the triathlon in 2 hours. t      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 357051: eric plans to compete in a triathlon. he can average 2 miles per hour in the 1/4-mile swim and 6 miles per hour in the 3-mile run. his goal is to finish the triathlon in 2 hours. to accomplish his goal what must his average speed, in miles per hour, be for the 15-mile bicycle ride?

the possible answers are: (1) 120/11 (2) 11 (3) 56/5 (4) 45/4 (5) 12
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
eric plans to compete in a triathlon. he can average 2 miles per hour in the
1/4-mile swim and 6 miles per hour in the 3-mile run. his goal is to finish
the triathlon in 2 hours.
to accomplish his goal what must his average speed, in miles per hour, be for
the 15-mile bicycle ride?
:
Let s = his average biking speed
:
Write a time equation: time = dist/speed
:
.25%2F2 + 3%2F6 + 15%2Fs = 2
Multiply by 6s, results:
3s(.25) + 3s + 6(15) = 2(6s)
:
.75s + 3s + 90 + 12s
3.75s - 12s = -90
-8.25s = -90
s = %28-90%29%2F%28-8.25%29
s = +10.91 mph biking speed, the fraction would be 120%2F11