Answer: Hello!
first let's note the things we already know:
there is a 16- lap race and the oval has one mile of length, then each of the laps has a length of one mile, and the whole race has 16 miles in total
Bobby averages 94 mph and already did 6 laps ( or 6 miles)
then we could write the Bobby equation as B(t) = 6 miles + 94mph*t
where t represents the time in hours.
now we could see how much time Bobby needs to end the race:
B(x) = 6mi + 94mph*x = 16mi
94mph*x = 16mi - 6mi = 10mi
x = (10/94)h = 0.106h
so Bobby needs 0.106 hours to finish the race, and we want to know which velocity Rick should have in order to reach the end of the race at the same time as Bobby.
Rick is starting the race, so he needs to do 16 miles in 0.106 hours, and as we know velocity is distance over time; so the average velocity of Rick is:
V = 16mi/0.106h = 150.9mph
Now let's see the hint:
Bobby does 8 miles in:
94*t = 8
t = 8/94 = 0.085 hours
and Rick does 10 miles in:
150.9*t = 10
t = 10/150.9 = 0.066 hours
wich is clearly different times, so maybe the hint is wrong.
