Answer
Running speed = 5 km/h
Cycling speed = 20 km/h
Work Step by Step
x = running speed
y = cycling speed
Monday = Equation 1 = .5x + .5y = 12.5
Tuesday = Equation 2 = .2x + .75y = 16
Multiply both equations by 100:
50x + 50y = 1250
20x + 75y = 1600
Solve for y in equation 1:
50y = 1250 - 50x
Divide both sides by 50:
y = 25 - x
Plug y into equation 2 and solve for x:
20x + 75(25 - x) = 1600
Expand and simplify:
20x + 1875 - 75x = 1600
-55x = -275
Divide both sides by -55:
x = 5
Plug x back into equation 1 and solve for y:
50(5) + 50y = 1250
250 + 50y = 1250
50y = 1000
Divide both sides by 50:
y = 20
