Answer
(a) The center will need 12.5 quarts of milk per week.
(b) 4 gallon containers will be needed for one week.
Work Step by Step
Compute how many cups of milk are needed, then convert to quarts and gallons.
Multiply amount per toddler by number of toddlers by number of days.
$\frac{2}{3}\times15\times5=\frac{30}{3}\times5=10\times5=50$
cups of milk are needed each week.
Convert to quarts.
$50 c\times\frac{1 qt}{4 c} = \frac{50}{4} qt = 12.5 qt$
Convert to gallons.
$12.5 qt\times\frac{1 gal}{4 qt}=\frac{12.5}{4} gal=3.125 gal$