If a federal reserve sets the reserve rate to 4%, what is the resulting money multiplier

Becca wants to mix fruit juice and soda to make a punch. she can buy fruit juice for $3 a gallon and soda for $4 a gallon. if she wants to make 28 gallons of punch at a cost of $3.25 a gallon, how many gallons of fruit juice and how many gallons of soda should she buy?

Me because i don't understand how to do it.: )

By january 2014 the us population had grown to 317.3 million and the us federal debt was a reported $17.3 trillion. calculate the january 2014 federal debt per capita. (round to the hundredths place)