Question

In a bike race, a rider covers a 5 mi flat stretch of road at a speed of s mi/h. She then doubles her speed down a hill 1 mi long. Finally, she reduces her downhill speed bu 12 mi/h as she rides the last 3 mi of the race. What function gives the time t it takes the rider finish the race in terms of s?

Answer 1

time = distance / speed

time at s mi/h = 5/s

time at 2s = 1/2s

time at 2s-12 = 3/(2s-12)

total time = 5/s + 1/2s + 3/(2s-12)
= (4s-11) / s(s-6)

Answer 2

9/(s)(2s)(2s-12)

Answer 3

I agree with #1