a.) Just divide the unit cost to the number of ounces given. Hence, the cost per ounce of each container would be:
$2.64/48 ounce = $0.055 per ounce
$3.84/64 ounce = $0.06 per ounce
b.) From the answers in part a, the lesser cost is the 48-ounce bottle amounting to just $0.055.
c.) For 48 ounce bottle price: 192*0.055 = $10.56
For 74 ounce bottle price: 192*0.06 = $11.52
Money saved = $11.52 - $10.56 = $0.96