Let the plane XY divides the points A(3,4,1) and B(5, 1, 6) in ratio k:1.
Hence, using section formula \((\frac{mx_2+nx_1}{m+n},\frac{my_2+ny_1}{m+n},\frac{mx_2+nz_1}{m+n})\)
On XY plane, Z co- ordinate of every point be zero, therefore
\(\frac{k\times6+1\times1}{k+1}\) = 0
6k + 1 = 0
k = - 1/6
The ratio is 1:6 externally in XZ plane which divides the line joined from points A and B.