C x=4y can no be true.
x=4y, total phonographs are 5y
5y cannot be 24 if y is an integer.
That depends on the total distance of the race, which you
have not bothered to mention.
If the team has exactly enough runners to run the entire race,
one at a time, then the number of runners needed is ...
(3) times (the total distance of the race, in miles) .
Your answer would be c and d because coefficients are the numbers that go in front of the variables. Have a nice day I hope this helped :)