Rate and unit rate PLEASE HELP I REALLY NEED TO FINISH THIS

Toyland is having a sale. all items are 20% off. how much will you save on an item that usually sells for 95$ explain your

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

What is the total surface area of this square pyramid?