Question

Barbara, Mark, and Carlos participated in the third heat of “The Big Race”. Barbara thought she could win with a 3 meter head start even though she only pedaled 3 meters every 2 seconds. Mark began at the starting line and finished the 20-meter race in 5 seconds. Meanwhile, Carlos rode his tricycle so that his distance (y) from the starting line in meters could be represented by the equation y = x + 1, where x represents time in seconds. Who would win in a 20 meter race?

Answer 1

Distance to travel = 20 m.
Let us determine the time, t, that each participant took to complete 20 m.

Barbara:
Average speed = (3 m)/(2 s) = 1.5 m/s
t = 20/1.5 = 13.3 s

Mark:
t =  5 s

Carlos:
y = x + 1
where
y = 20 m
x = time, t
Therefore
t =x = y - 1 = 20 - 1 = 19 s

Summary:
Barbara:  13.3 s
Mark:       5 s
Carlos:     19 s

Answer:
The winner is Mark