The bulk warehouse has 48 cans for $12.00 so that's 12/48 = $0.25 a can
The local grocery store has 12 cans for $6.00 so that's 6/12 = $0.50 a can
The grocery store offer is $0.50 a can and the warehouse is $0.25 a can so the grocery store is .50-.25 = $<<0.50-.25=0.25>>0.25 more expensive per can
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