
Andy C. answered 10/07/18
Tutor
4.9
(27)
Math/Physics Tutor
We know nothing about Mary, so call her X
Joe: 3x
Deandre: X+9
Altogether: x + 3x + x + 9 = 84
5x + 9 = 84
5x = 75
x = 15
Mary 15
Joe 45
Dandre 24