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
36 girls
step-by-step explanation:
the 48 boys is 4 parts of the ratio
divide 48 by 4 to obtain one part of the ratio
= 12 ← 1 part of the ratio
3 parts = 3 × 12 = 36 ← number of girls
a and c