SOLUTION: A cyclist travels for x hours at 5km/h and for y hours at 10km/h.he travels 35km altogether and his average speed is 7km/h. find x and y

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Question 1071363: A cyclist travels for x hours at 5km/h and for y hours at 10km/h.he travels 35km altogether and his average speed is 7km/h. find x and y
Answer by josgarithmetic(39623) About Me  (Show Source):
You can put this solution on YOUR website!
            SPEED   TIME      DISTANCE
Part1        5       x           5x
Part2        10      y           10y
Total              x+y           35
AVERAGE      7


Average speed is total distance divided by total time.

system%2835%2F%28x%2By%29=7%2C5x%2B10y=35%29

Note that total time can be found just from the average speed, the first equation.

x%2By=35%2F7
x%2By=5------ 5 hours total time.

-
5x%2B10y=35
x%2B2y=7

Revised system:
system%28x%2B2y=7%2Cx%2By=5%29

highlight%28y=2%29
-
highlight%28x=3%29