Find the ratio in which the line segment joining the points A(3,8) and B(-9, 3) is divided by the Y- axis.

Let the ratio in which the line AB is divided by the y-axis be k : 1. 
The point on the y - axis be (0, y).  

\[\left( 0, y \right) = \left( \frac{k \times \left( - 9 \right) + 1 \times 3}{k + 1}, \frac{k \times 3 + 1 \times 8}{k + 1} \right)\]

\[ \Rightarrow \left( 0, y \right) = \left( \frac{- 9k + 3}{k + 1}, \frac{3k + 8}{k + 1} \right)\]

\[ \Rightarrow 0 = \frac{- 9k + 3}{k + 1} \]

\[ \Rightarrow - 9k + 3 = 0\]

\[ \Rightarrow k = \frac{1}{3}\]

Thus, the ratio is 1 : 3.