
Lauren H. answered 08/07/18
Tutor
4.8
(24)
Experienced High School Chemistry Teacher
Let s = staff; let a = administrators; let f = faculty
Three unknowns means three equations.
#1) f + s + a = 320
#2) f = s + a
#3) s - 60 = a
From # 1, f = 320 - s - a
From # 2, f = s + a, so, 320 - s - a = s + a
Simplify: 320 = 2s + 2a
160 = s + a
Therefore, from #1, f = 160
Therefore, s + a must = 160
From #3, s - 60 = a, so s + s - 60 = 160
Solve: 2s = 220, so, s = 110
Therefore, a = 50 (from #1)