A difference in quantity of materials used on two comparable jobs may be caused by a. employee carelessness b. poor quality materials c. inadequately trained employees d. All of these choices are correct.

d.All of these choices are correct.

Explanation:

All the above can result in different quantities of materials being used for comparable jobs.

Employee Carelessness can cause more material to be used if they fail to adequately measure the Requirements of a job. If they are also careless in the usage of the material, there will be wastage and therefore a larger use of materials.

Poor Quality Materials can also result in different quantities being used because for instance, more material could be required to do something that a stronger material could have easily done.

Inadequately trained Employees is a major reason for Material Wastage. If employees are not trained by seasoned people who know how to reduce wastage, that knowledge could take time to come to them. If they were adequately trained however, they can master the tricks on wastage avoidance and limit discrepancies in the amount of materials used per comparable jobs.