Question

The ratio in which the plane 2x - 1 = 0 divides the line joining (-2,4,7) and (3, -5, 8) is

• A. 2 : 3
• B. 4 : 5
• C. 7 : 8
• D. 1 : 1

Answer 1

The correct option is D 1 : 1

Let the required ratio be k:1, then the coordinates of the point which divides the join of the points (-2, 4, 7) and (3, -5, 8) in this ratio are given by $(\frac{3k-2}{k+1},\frac{-5k+4}{k+1},\frac{8k+7}{k+1})$
As this point lies on the plane 2x - 1 = 0.
$(\frac{3k-2}{k+1}=\frac{1}{2}\Rightarrow k=1)$ and thus the required ratio as 1:1.