Question

The ratio in which the line joining the points (a, b, c) and

(–a, –c, –b) is divided by the xy-plane is

• A. $a:b$
• B. $b:c$
• C. $c:a$
• D. $c:b$

Answer 1

Answer: (D)

$c:b$

Answer 2

Let the ratio be k : 1. Since on xy-plane z = 0

$\Rightarrow \frac { - b k + c } { k + 1 } = 0 \Rightarrow k = \frac { c } { b }$. Hence the ratio is c : b.

Aliter : Using formula, required ratio is