Using a system of equations, it is found that the correct option is:
A) 1389x+1660y=787x+1121y.
<h3>What is a system of equations?</h3>
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
In this problem, considering the amounts in each olympics(1389 men and 787 women participated on the 19th, 1660 men and 1121 women in the 22th), the system is:
A) 1389x+1660y=787x+1121y.
More can be learned about a system of equations at brainly.com/question/24342899
Answer:
No, she is not correct as her speed is 0.25 miles per minute.
Step-by-step explanation:
Given:
Ratio of distance to time taken is 15 : 60.
Distance is in miles and length of time is in minutes.
We know that, average speed is given as the ratio of the distance traveled and the length of the time taken.
So, the ratio above is nothing but the average speed of Reese for cycling.
Thus, average speed of Reese is given as:

Therefore, the average speed of Reese is 0.25 miles per minute which is not equal to the one mentioned by Reese as 4 miles per minute.
So, Reese conclusion of her average speed is incorrect. It's not 4 but the reciprocal of 4 which is 0.25 miles per minute.
See the file attached and let me know whether you understand the explanation.