Which numerical expression represents 1/2 the sum of 7 and 5?

Mr switzer needs to buy new 1-foot tiles to cover his bathroom floor. the floor is 12 feet long and 8 feet wide. each square foot of tile will cost $1.79. in dollars what will be the total cost of the tiles he needs to buy.

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?

Sarah took the advertising department from her company on a round trip to meet with a potential client. including sarah a total of 11 people took the trip. she was able to purchase coach tickets for $280 and first class tickets for $1280. she used her total budget for airfare for the trip, which was $6080. how many first class tickets did she buy? how many coach tickets did she buy?