Answer:1) Economy
2)The writing should be arranged on three subhead,prewriting,main writing and conclusion.
3) 15minutes
Explanation:in the first scenario, involves an intern,the cost to the customer,of the repair was not stated ,so the economy aspect wasn't addressed in the letter.
2) Business letters should follow a pattern,why,how and when.why tells the recipient the purpose if the letter while the How depicts how the writer intends to gather his thoughts on how to go about the writing.thus depend on the audience and the when is about when the to send the mail,it must be timely and must meet the requirements of the business.
3)The pre writing will take 15 minutes that is a quarter of an hour to put his thoughts together in writing.the pre writing is when the main ideas are pen down ,it is when the bulk of the work is done.every other aspect will depend on this stage
