Given that;
a.
He can buy 64 fl oz at the grocery store for $2.00.
So, the unit price for the grocery store will be;
b.
Also, He can buy 256 fl oz at the wholesale club for $7.50.
So, the unit price for the wholesale club is;
c.
So, for Ben to buy at the best deal he should buy at the wholesale club. This is the wholesale club has a lower unit price when compared to the grocery store.