Gavin went on 24 runs last month that totaled 100 miles. Each run was a distance of either 3 miles or 5 miles. Which system of equations can be used to determine the number of 3-mile runs, x, and the number of 5-mile runs, y, that Gavin went on last month?
A.
x + y = 100
3x + 5y = 24
B.
x + y = 100
5x + 3y = 24
C.
x + y = 24
3x + 5y = 100
D.
x + y = 24
5x + 3y = 100
