Graphical Evaluation of Discrete Time Convolution

A signal $h[n]$ is nonzero only for $-2 \le n \le 4$. For what range is $h[-k]$ nonzero?

A signal $h[n]$ is nonzero only for $-2 \le n \le 4$. For what range is $h[10-k]$ nonzero?

A signal $h[n]$ is nonzero only for $-2 \le n \le 4$. A signal $x[n]$ is nonzero only for $0 \le n \le 4$. For what range of $n$ can the convolution $h[n]*x[n]$ be nonzero?

Let $y[n] = u[n]*u[n]$ where $u[n]$ is the unit step function. Select all of the answers that are true below.

Let $x[n] = \left\{ \begin{array}{cl} 1, & 0 \le n \le 10\\ 0, & \mbox{otherwise} \end{array} \right.$ and $h[n] = \left\{ \begin{array}{cl} 1, & 0 \le n \le 5\\ 0, & \mbox{otherwise} \end{array} \right.$. Define $y[n] = x[n]*h[n]$ and select all of the true statements below.