Question 226005
Torque left home on his bicycle at 9:00 A.M., traveling at an average rate of 12 mph. At noon, Torque's brother set out after him on a motorcycle, following the same route, averaging 39 mph. How long had Torque been riding when his brother caught up?
.
You will need to apply the "distance formula"
d = rt
where
d is distance
r is rate or speed
t is time traveled
.
For his brother to catch up:
"distance Torque road on bicycle" = "distance his brother rode"
.
Let t = time Torque rode on his bicycle
then
t-3 = time his brother traveled on motorcylce
.
12t = 39(t-3)
12t = 39t-117
0 = 27t-117
117 = 27t
4.333 = t
Or 
4 hours and 20 minutes