advertising campaign: If you pay your child $7 to go buy $100 worth of groceries, then your child makes twice as much on the trip as we do. Youve collected the following information from the grocery chains financial statements:

($ in millions)
Sales	$	680.0
Net income		23.8
Total assets		440.0
Total debt		310.0

a.	What is the profit margin for the child as a percentage of what they spend and the profit margin for the store? (Do not round intermediate calculations. Enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.)
b.	What is the store's ROE? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.)