Answer:
72 yd / min
Step-by-step 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