Abagel cost $0.80.on wednesday ,a dozen bagels cost $6.00. what is the unit price of a bagel on wednsday, if you buy 3 bagels? if you buy a dozen bagels?

If a bagel costs $0.80 any day, then the unit price
is $0.80 per bagel.

If the unit price of a bagel is $0.80 , then every bagel
you buy costs $0.80 .

Only one thing changes:  The price of a dozen on Wednesday.

If you buy 1 dozen ... or any number of dozens ... on Wednesday,
then the unit price of the contents of that bag is

                        ($6.00) / (1 dozen)  =  $6.00 per dozen

If you want to convert that to a
different unit of measure, then
you do it like this:

                 (6.00  $/dozen) x (1 dozen/12 bagels)

             =  (6.00 x 1 / 12)  ($/bagel)

             =        0.5  $/bagel

                 or   $0.50 / bagel .