Three friends are comparing the prices of various packages of golf balls at a sporting good store. Hector finds a package of gold balls that cost $4.50. (go to the next question on my page for the rest of the screenshots)

water molecules will move from the side of higher water concentration to the side of lower concentration until both solutions are isotonic. at this point, equilibrium is reached. in an isotonic solution, the flow of water in and out of the cell is happening at the same rate.

hope this < 3

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads