Question

If $a,(a-2)$ and $3a$ are in AP, then the value of $a$ is

• A. $-3$
• B. $-2$
• C. $3$
• D. $2$

Answer 1

The correct option is B $-2$

$\text{Since a, a-2 and 3a are in AP}$
$\therefore$ $a-2-a=3a-(a-2)$

$\Rightarrow -2=2a+2$
$\Rightarrow 2a=-4$
$\Rightarrow a=-2$
Option B is correct.