What point divides the join of $A(1, 2, 3)$ and $B(3, 4, 5)$ externally in the ratio 2 : 1?

Explanation

1. 01

   External division: $\frac{m\vec{b} - n\vec{a}}{m - n}$ with $m = 2$, $n = 1$.

2. 02

   $2(3, 4, 5) - (1, 2, 3) = (5, 6, 7)$.