If the position vector of a point A is $\vec a + 2\vec b$ and $\vec a$ divides AB in the ratio 2: 3, then the position vector of B is
Answer & explanation
Correct answer: option 3
Let $P (\vec a)$ divide AB in the ratio 2 : 3 and let$\vec c$ be the position vector of B. Then,
$\vec a=\frac{2(\vec c)+3(\vec a +2\vec b)}{2+3}$
$⇒\vec c=\vec a-3\vec b$
