Question

(5) Rhea ran 6 laps on a track. Each lap is 200 yards. Rhea's average speed for

the first two-third of her run was 80 yards per minute, and for the rest of her
run she averaged 60 yards per minute. What is Rhea's average speed for the
entire run?

Answer 1

72 yd / min

Explanation:

The first thing is to fully calculate the distance traveled, each lap is 200 yards and how 6 laps would be:

200 * 6 = 1200

Now, let's divide the race into how the statement tells us:

1200 * 2/3 = 800

1200 * 1/3 = 400

That is, in the first 800 yards it goes to 80 yd / min and then in the remaining 400 yards it goes to 60 yd / min, let's calculate the time Rhea lasted:

800/80 = 10 min

400/60 = 6,667 min

Which means that in total it would be:

10 + 6,667 = 16,667

In other words, Rhea took 16,667 minutes to travel 1,200 yards, so the speed would be:

1200 / 16,667 = 72

Therefore the average Rhea speed was 72 yd / min