Questions

A spoofing attack is a situation in which one individual or program effectively disguises or mask as another by falsifying information and thereby gaining up an ill-conceived advantage. It may use for stealing password or IP addresses.

One word substitute for A person who loves everybody is Altruist. Altruism is the belief that the well-being of others is equally, if not more, important than the well-being or survival of the self. Further, altruism involves selfless acts or undertakings that put the welfare of others before one's own.

Let M and m grams be the mass of boat + rock in it. By law of floatation(M+m) grams of water will be displaced. This has a volume of (M+m)cc. That means the level of water in pool has risen up by (M+m)cc with the boat + rock when it is floating. If the rocks in the boat are thrown not into the pool but outside, the weight left is only M grams the weight of the boat. This will have displaced M cc of water only i.e less water than in the case of loaded boat. But if the rocks are put in the water in the pool and not outside, then the water in the pool will rise not only by M cc on account of empty boat but also by a volume of the stone put into it. This volume will be mdwhere m is the mass of rock and d density of rock.

Now md is  < m. Thus the total rise will be M+mdwhich is < M + m.

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.