Question

Two riders are in a bike race. The second rider starts half an hour late but rides 4 miles per hour faster than the first rider. If they both finish 3 hours after the race starts, how fast are they each riding?

Answer 1

d=rt
Now, the distance that the two riders travel is the same.
The first rider rides for 3 hours, while the second rides for 2.5 hours.
The first rider travels at x mph, while the second travels at (x+4) mph.
So:
\[d=3x\]\[d=2.5(x+4)\]\[2.5(x+4)=3x\]The first rider travels at 20 mph, while the second travels at 24 mph.