How long will it take eden to be a full lap ahead of emma in terms of seconds

Question

Emma and Eden are racing around the Chick-Fil-A drive through which has a distance of 500 feet. If Emma is running 11 feet per second and Eden is running 15 feet per second, how long will it take Eden to be a full lap ahead of Emma in terms of seconds?

Answer 1

Distance = Rate x Time

t = time elapsed since both started.

Eden distance = 15t; Emma distance = 11t

Eden distance - Emma distance = 500

15t - 11t = 500 -> 4t = 500 -> t = 500/4 = 125 sec.

Check: In 125 sec, Eden goes 125(15) = 1,875 ft (3.75 laps). In 125 sec Emma goes 125(11) = 1,375 ft (2.75 laps)