There are 18 girls in a class. If this is 40% of the class list, then how many students are in the class list?

There is 45 students in the class

Step-by-step explanation:

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