Question

jodie bicycles 7 km/h faster than carlos. in the same time it takes carlos to bicycle 57km, jodie can bicycle 78 km. how fast does each bicyclist travel?

Answer 1

let x = carlos's speed
jodie: x + 7

x * t = 57
(x + 7) * t = 78
solve for t and equate

t = 57/x
t = 78 / (x + 7)
\[\frac{57}{x} = \frac{78}{x + 7}\]
57(x + 7) = 78x
57x + 399 = 78x
21x = 399
x = 19
carlos bikes at 19 km/hr
jodie bikes at 26 km/hr