Questions

Sum of all numbers in each row and columns must be 15.

In last row to gt sum as 15 missing number must replaced by 1. 

A relational database is a digital database based on the relational model of data, a database structured to recognize relations between stored items of information. A software system used to maintain relational databases is a relational database management system.

Computer database in which all data is stored in Relations which (to the user) are tables with rows and columns. Each table is composed of records (called Tuples) and each record is identified by a field (attribute) containing a unique value. Every table shares at least one field with another table in 'one to one,' 'one to many,' or 'many to many' relationships. These relationships allow the database user to access the data in almost an unlimited number of ways, and to combine the tables as building blocks to create complex and very large databases.

Internet Protocol version 4 (IPv4) which defined an IP address as a 32-bit value

IPv4 is in contrast to IPv6, which defined an IP address as a 128 bits value.

WBR that is World Book of Records, the London based organization that focuses on maintaining and cataloging the world records has awarded the title of 'Most visited place in the World' to the famous Golden Temple. This holy Shrine has recorded quite an uplift after the successful Heritage street project carried out by the Amritsar department. 

Sri Harmandir Sahib, also known as Golden Temple and the Darbar Sahib, is the holiest Gurdwara and the most important pilgrimage site of Sikhism. It is located in the city of Amritsar, Punjab, India.

Alum is a common alum, potassium aluminum sulphate K2SO4.Al2SO43.24H2O which makes colloidally suspended impurities in water such as clay to settle down.