
Chaarushena D. answered 04/09/19
Yale Law School First Year, Biological Engineering B.S. from MIT
This is a system of equations!
If we make "c" = the number of children and "a" = the number of adults, we get two equations:
c+a = 357
2.75*c + 6.80*a = 1731
If we solve using substitution, we get that a = 357-c, which we can plug into the second equation to get a single equation with a single formula:
2.75*c + 6.80*(357-c) = 1731 -> c = 172
Plugging this into the first equation:
a = 357 - 172 = 185.
185 adults and 172 children attended.