Ann entered a race which required a run of 10 km north and a bike of 120 km west. Determine her running speed if she cycled ten times faster than she ran and the total race took her four hours to complete.

x - running speed10x - speed on bikev = s/ts - distancet - timet = s/vs₁ = 10 kms₂ = 120 km[tex]\frac{10}{x} + \frac{120}{10x} = 4\\\\\frac{10}{x} + \frac{12}{x} = 4\ \ //*x\\\\10 + 12 = 4x\\\\4x = 22\ \ //:4\\\\x =\frac{22}{4} = 5,5\ km/h[/tex]Solution:Running speed = 5,5 km/h