Base on the question where as asking to complete the passage and base on my research and further investigation, One of the way to develop a main idea for the advertisement is to conduct product research. I hope you are satisfied with my answer and feel free to ask for more if you have question and further clarification
the authors purpose was to simply teach you and entertain at the same time the author is explaining that even though he was nervous of his new coming year he had noticed hope through his friends and his teacher
Each shirt=25.95
Total=519
Divide total shirts by each shirt:
519/25.95=20
