please explain how to do this

As the production planner for Xiangling Hu Products, Inc., you have been given a bill of material for a bracket that is made up of a bas 1 spring, and 3 clamps. The base is assembled from 2 clamps and 2 housings. Each clamp has 1 handle and 2 castings. Each housin has 2 bearings and 1 shaft. There is no inventory on hand. This exercise contains only parts b and c. The product structure is as follows: b) Determine the gross quantities needed of each item if you are to assemble 75 brackets. Base: units (enter your response as a whole number). Spring: units (enter your response as a whole number). Clamp: units (enter your response as a whole number). Housing: units (enter your response as a whole number). Handle: units (enter your response as a whole number). Casting: units (enter your response as a whole number). Bearing: units (enter your response as a whole number). Shaft: units (enter your response as a whole number). c) Compute the net quantities needed if there are 25 of the base and 75 of the clamp in stock. Base: units (enter your response as a whole number). Spring: units (enter your response as a whole number). Clamp: units (enter your response as a whole number). c) Compute the net quantities needed if there are 25 of the base and 75 of the clamp in stock. Base: units (enter your response as a whole number). Spring: units (enter your response as a whole number). Clamp: units (enter your response as a whole number). Housing: units (enter your response as a whole number). Handle: units (enter your response as a whole number). Casting: units (enter your response as a whole number). Bearing: units (enter your response as a whole number). Shaft: units (enter your response as a whole number)