Questions

From first figure : each fig has the value of 20 => It has inside 4 figures => Each individual figure has the value of '5'

From second => Each Triangle has the value of '1' (bcoz it contains two in each)

From third => Figure star has the value of '4'

Then in fourth => 4 + 1 + 15 = 20

C++ is not an Operating System.

An Operating System is a collection of system programs that manages all the other programs application programs in a computer as well as the allocation and use of hardware resources such as the CPU, Memory and the Hard Disk Drive.

It acts as an interface between the hardware and the user level program.

It controls and facilitates the overall operation of a computer. 

Here

UNIX : UNIX is a popular multi-user, multitasking operating system (OS) developed at Bell Labs.

Windows NT : Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993.

DOS : DOS is Disk Operating System. The term DOS can refer to any operating system.

C++ : C++ is a programming language and computing platform.

Hence, C++ is not an Operating System.

Hydrogen is the common element in all acids.

Sulphur is an yellow element that stinks when burned.

Artificial Intelligence is associated with Fifth Generation Computers.

Artificial Intelligence is an area of Computer Science concerned with making the computer perform tasks which, to be successfully done by human beings, require intelligence.

AI is a reality made possible by using parallel processing and superconductors. Computer devices with artificial intelligence are still in development, but some of these technologies are beginning to emerge and be used such as voice recognition.

The shape of two fingers shown up will be in 'V' and it represents in Roman letters, a number 5.