Questions

The logic in this puzzle is summing the result of [subtraction of upper two digits] & [addition of lower two digits] 

Hence, the result is  

(5 - 3) + (2 + 8) = 2 + 10 = 12.

a.Direct interaction with customers: The retailer acts as the final link between the organisation and its customer. The retailer knows his customer better than anyone. He even suggests the customer what to purchase and allows him credit facilities to encourage frequent buying behaviour in the customer.

b.Small purchases: The customer purchases goods in small lots from the retail stores. So there are frequent visits to the retail store by the customer.

c.Instrument of marketing communication: via which information about the product is disseminated to the needy customers

Para-amino salicylic acid (PAS) is used in the treatment of Tuberculosis.

In the OSI model of computer networking, a frame is the protocol data unit at the data link layer. Frames are the result of the final layer of encapsulation before the data is transmitted over the physical layer.

A single packet on a data link is known as Frame.

Metropolis is a central city with the developed area surrounding it while Megalopolis is a region made up of 2 or more metropolitan areas.