Nonexempt work is that work which is not sales work and is not performed incidental to and in conjunction with the outside sales activities of the employee. It includes outside activities like meter-reading, which are not part of the sales process. Inside sales and all work incidental thereto are also nonexempt work. So is clerical warehouse work which is not related to the employee's own sales. Similarly, the training of other salesmen is not exempt as outside sales work, with one exception. In some concerns it is the custom for the salesman to be accompanied by the trainee while actually making sales. Under such circumstances it appears that normally the trainer-salesman and the trainee make the various sales jointly, and both normally receive a commission thereon. In such instances, since both are engaged in making sales, the work of both is considered exempt work. However, the work of a helper who merely assists the salesman in transporting goods or samples and who is not directly concerned with effectuating the sale is nonexempt work.