(a)[1]
The scale in the diagram runs from $3.8$ to $3.9$ and is divided into five equal intervals. What value is shown at the mark labelled $P$?
(b)[1]
Points $X$ and $Y$ are on the line $AB$ with $AX:XY:YB = 3:2:4$. The length of $AB$ is $18\text{ cm}$. Determine $XY$.