Question

The ratio in which the line segment joining the points $(4, 8, 10)$ and $(6, 10, - 8)$ is divided by xy-plane is

• A. 5 : 4 externally
• B. 5 : 4 internally
• C. 3 : 2 externally
• D. none of these

Answer 1

Answer: (B)

5 : 4 internally

Answer 2

Let $xy$-plane divide the join of points $(4, 8, 10)$ and $(6, 10, - 8)$ in the ratio $\lambda : 1$
$\frac{10 - 8 \lambda}{\lambda +1}$ = 0 $\Rightarrow \, 10 - 8 \lambda$ = 0 $\Rightarrow \, \lambda = \frac{5}{4}$