math
posted by chris .
A cyclist and a jogger start from a town at the same time and headed for a destination 24 mi away. The rate of the cyclist is twice the rate of the jogger. The cyclist arrives 3hrs ahead of the jogger. Whats the rate of the cyclist?

C = 2J (rates)
Distance = rate/time
Therefore, time = rate/distance
J/24  C/24 = 3
Use substitution to solve first for cyclist and then for jogger. 
is the answer 12

Sorry, I goofed!
Distance = rate * time
Therefore, Time = Distance/rate
24/J  24/C = 3
Substitute 2j for C.
24/j  24/2J = 3
Multiply both sides by J.
24  12 = 3J
12 = 3j
4 = J
C = 2J = 2 * 4 = 8
Sorry for the goof! This should help.