1. If the average of three numbers is V. If one of the numbers is Z and another is Y, what is the remaining number?

A. ZY - V
B. Z/V - 3 - Y
C. Z/3 - V - Y
D. 3V- Z - Y
E. V- Z - Y

Question

1. If the average of three numbers is V. If one of the numbers is Z and another is Y, what is the remaining number? 

A. ZY - V 
B. Z/V - 3 - Y 
C. Z/3 - V - Y 
D. 3V- Z - Y 
E. V- Z - Y

anonymous · Answer

I do this by starting with an equation I know. Let's call the third, remaining value X.
(X+Y+Z)/3 = V
Then solve for X. To do this, start by multiplying both sides of the equation by 3. Then subtract Y from both sides of the equation. Then subtract Z from both sides of the equation. That should isolate X so you'll have something like "X = ________". That right part of the equation should match one of the choices. Let me know if you need help along the way! I hope my suggestions are helpful!