The average of X, Y and Z is 2X. If the average of Y and Z is 20, then what is the value of X?
The average of X, Y and Z is 2X.
$$\frac{X+Y+Z}{3}\ =2X$$Â Â Eq.(i)
If the average of Y and Z is 20.
$$\frac{Y+Z}{2}\ = 20$$
Y+Z = 40Â Â Â Eq.(ii)
Put Eq.(ii) in Eq.(i).
$$\frac{X+40}{3}\ =2X$$
X+40 = 6X
6X-X =Â 40
5X = 40
X = 8
Value of X = 8
Create a FREE account and get: