George has a storage unit already occupied by a large container that is the same height of the whole unit. How much space is left for storage?

945 m³

Step-by-step explanation:

Space left for storage = Volume of storage unit - volume of the container

Storage unit:

length = l = 15.3 m

Height = h = 10 m

Width = w = 7 m

Volume of storage unit = l * w *h

                                      = 15.3 *7* 10

                                      = 1071  m³

Container:

length = l =4.2 m

Height = h = 10 m

Width = w = 3 m

Volume of container = l * w *h

                                      = 4.2 *3* 10

                                      = 126 m³

Space left = 1071 - 126  = 945 m³

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