A plane meets the co-ordinate axes in A,B,C such that the centroid of the triangle ABC is the point (p,q,r). The equation of the plane is
The equation of plane is
xA+yB+zC=1 ……. (1)
Using centroid formula in XYZ plane is
(x=x1+x2+x33,y=y1+y2+y33,z=z1+z2+z33)
Then,
(A3,B3,C3)=(p,q,r)
Therefore,
A=3p,B=3q,C=3r
Put the value of A,B and C in equation of plane (1) and we get
xA+yB+zC=1
x3p+y3q+z3r=1
Hence,
xp+yq+zr=3
option (D) is correct answer.