In response to complaints about high prices, a grocery chain runs the following advertising campaign: $"$If you pay your child $$1$ to go

buy $$32$ worth of groceries, then your child makes about twice as much on the trip as we do$."$ You've collected the following

information from the grocery chain's financial statements:

a$.$ What is the child's profit margin?

Note: Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$

b$.$ What is the store's profit margin?

Note: Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$

c$.$ What is the store's ROE?

Note: Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$