Which expression is equivalent?

Can someone me out here and the tell me the greatest common factor

Julia bought 7 hats a week later half of all her hats were destroyed in a fire. there are now only 12 hats left with how many did she start

Anne plans to increase the prices of all the items in her store by 5%. to the nearest cent, how much will an artist save if the artist buys a canvas and a frame that each measure 24 by 36 inches before the price increase goes into effect?