Questions

Mumbai has been ranked the world's second most densely populated city with 31,700 people per sq km, by the World Economic Forum (WEF) citing UN Habitat Data. Bangladesh's capital Dhaka topped the list with 44,500 people per sq km. Rajasthan's Kota has been ranked the world's seventh most densely populated city with 12,100 people per sq km.

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. 

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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.

Karst is a type of landscape that is characterized by caverns, caves, sinkholes, and underground streams. These features were all caused by erosion of the underlying rock.

Limestone type of rock usually underlies a karst landscape.

Narmada rises near Amarkantak