Question 154360
Elena bicycles 5km/h faster then Carlos. In the same time it takes Carlos to bicycle 39km, Elena can bicycle 54km. How fast does each bicyclist travel?
:
Let s = C's speed
then
(s+5) = E's speed
:
it says the times are equal: write a time equation: time = dist/speed
:
{{{54/(s+5)}}} = {{{39/s}}}
cross multiply
54s = 39(s+5)
:
54s = 39s + 195
:
54s - 39s = 195
:
15s = 195
s = {{{195/15}}}
s = 13 km/hr is C's speed
then
13 + 5 = 18 km/hr is E's speed
:
:
Check solutions by finding the times
54/18 = 3 hr
39/13 = 3 hr