Aclothing store bought packages of three pairs of socks for $1.75. the store owner marked up thebprices by 80%.

a) $3.15

b) $1.75

Step-by-step explanation:

a.  The $1.75 wholesale price is marked up by 80%.  To find the markup, find 80% of $1.75 by multiplying $1.75 by 0.80 and add the result to the wholesale price:  $1.75 + 0.80($1.75) = $3.15.  The retail price is thus $3.15.  It's equivalent and faster to multiply the wholesale price by 1.80 to get the retail price in one step.

b) The retail price will be less than the wholesale price if the store marks this merchandise down.  Following the example in (a), above:

New retail price:  $3.15(1.00 - 0.20) = $3.15(0.80) = $1.75 (this is the original wholesale price).