The piece of code shown creates two processes. Therefore, we have a total of three processes, the parent, the first and second child. Each of these has its own private copy of the variable $\textsf{c}.$ For the parent, the variable $\textsf{c}$ be $20$ before the end of the program. For the first child (the one created in the first program statement), the variable $\textsf{c}$ will contain the value $10$ before the end of the program. For the second child (the one created in the else clause), the variable $\textsf{c}$ will contain the value $15$ before the end of the program.
