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
Answer:
Number of large boxes: 55
Number of small boxes:65
Step-by-step explanation:
Let be "l" the number of large boxes and "s" the number of small boxes.
Set up a system of equations:

Use the methof of elimination. Mulitply the first equation by -60 and add both equations. Then solve for "s":

Substitute s=65 into any of the original equations and solve for "l":

Answer:
b
Step-by-step explanation:
Is this all the information that you have
Answer:
"Dominic lived in Spain for 13 months and Columbia for 7 months."
Step-by-step explanation:
let months stayed in spain be "s" and months stayed in columbia be "c"
We can write 2 equations.
Since, lived in Spain and Columbia for a total of 20 months, we can write:
s + c = 20
Also, since 120 words per month in Spain and 150 words per month in Columbia for a total of 2610 new words, we can write:
120s + 150c=2610
Solving first for s:
s = 20 - c
Putting in 2nd and solving:
120(20 - c) + 150c = 2610
2400 - 120c + 150c = 2610
30c = 210
c = 7
Now,
s = 20 - c = 20 - 7 = 13
So
"Dominic lived in Spain for 13 months and Columbia for 7 months."