anybody here to give me notes to solve this question

(A and B are two points on a pipe of diameter 600 mm. the grid reference for the two points are given in the below , together with the elevation of the top of the pipe at these points. A drain pipe is being planned, and P and Q (also shown in the table) are two points long the route of this drain. it is planned that the drain should have the largest possible slope-point the minimum distance between the top of the water supply pipe and the bottom of drain is to be 500 mm.
what is the maximum possible slop for drain and what will be elevation of the top of the drain at Q point
1- draw the pipe line centrelines to scale on the squared paper provided to determine the point intersection
determine the equation for two pipelines and calculate the coordinates of the point of intersection

Are you able to understand the problem without the accompanied plan/sketch?

If you can, kindly describe what you understand in words, or post a link to the plan.
Thank you.