In in interoffice memo, is this correct? First, I would like Bob,Sales Mgr to provide a sales analysis for 2 years. Next,from Mary, Human Resources, a summary of the hiring policy.
I need to request this information from these employees, and put it in one paragraph.

Well looks pretty good just like that.
Obviously the tone changes dependent on your position within the company, after all the Tea Boy won't ask for this information in the same way as the CEO.
So what does your homework say about that aspect of this task ?

In in interoffice memo, is this correct? First, I would like Bob,Sales Mgr to provide a sales analysis for 2 years. Next,from Mary, Human Resources, a summary of the hiring policy.
I need to request this information from these employees, and put it in one paragraph.

You have two very different requests. Why do you think they have to be put in one memo?

Use two memos.

Because I am required to explain what I need from each employee by name in one paragraph.

Who requires you? Is this homework?

It is very bad business practice to put each in the same paragraph, and it would require two separate emails.

To include them together, shows lack of respect for either as you are not giving them the respect of a memo for their specific duties.

This would look bad by both higher up management and be an issue for those receiving.

If this is homework, they are wrong and my address to the class would be that the assignment is asking for something improper in business.