SOLUTION: The average of x,y,z and 40 is 10. What is the average of x,y and z?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: The average of x,y,z and 40 is 10. What is the average of x,y and z?      Log On


   

Question 868886: The average of x,y,z and 40 is 10. What is the average of x,y and z?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Average the four given values

(x+y+z+40)/4 = 10

Then isolate x+y+z

(x+y+z+40)/4 = 10
x+y+z+40 = 10*4
x+y+z+40 = 40
x+y+z = 40-40
x+y+z = 0

Then divide this sum by 3 to average x,y,z

(x+y+z)/3 = 0/3
(x+y+z)/3 = 0

So they average out to 0.