Could anyone help me to solve this two questions?

Ex. 2.2 | (15pts) The following shows three different ways a process can be created. 1. A human user explicitly commands the OS to run a program by double-clicking the program icon or typing a command. 2. A currently running process creates a sub-process (also known as a child process) prompted by an external event (a human user's request, an event caused by another process). 3. A currently running process creates a child process explicitly executing an instruction such as fork(). The third case, in which a currently running process creates a new process, in general covers the first two cases. Explain why. Ex. 2.3 | (15pts) Write a small program that uses fork() and exec() to run the Is command