48/6 = 8
He needs to buy 8 of the six pack size for a total of :
8 x 12.12 = $96.96
Or
48/ 4 = 12 Of the 4 packs for a total of
12 x 9.72 = $116.64
He would save
116.64 - 96.96 = $19.68 by buying 8 of the six packs.
The value of 64/225 is in the lowest state, but in decimal form, the value equals 0.284444
12 is the answer
Hope this helps