Q15

Consider the following function. Function F(n, m:integer):integer; begin if (n<=0) or (m<=0) then F:=1 else F:F(n-1, m) + F(n-1, m-1); end; Use the recurrence relation $\begin{pmatrix} n \\ k \end{pmatrix} = \begin{pmatrix} n-1 \\ k \end{pmatrix} + \begin{pmatrix} n-1 \\ k-1 \end{pmatrix}$ to answer the following questions. Assume that $n, m$ are positive integers. Write only the answers without any explanation.