Question

The ratio in which the line joining $(3,4,-7)$ and $(4,2,1)$ is dividing the xy-plane

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

Answer 1

The correct option is C $7:1$

Let the given points be

$A(3,4,-7),B(4,2,1)$

Let a point on $XY-plane$ be $P(x,y,0)$ and the line $AB$ in the ratio $k:1$

then by section formula

$0=\frac{k\times 1+1\times -7}{k+1}$

$k-7=0$

$k=7$

Therefore, ratio is $7:1$

Hence, option $C$ is correct.