You are a birdwatcher listening for bird calls in a quiet park on a peaceful April day. Based on your experience, you hear an average of one bird call per minute. Also, when you hear a bird call, it's a robin $\frac{1}{2}$ of the time, a woodpecker $\frac{1}{3}$ of the time, and a sparrow $\frac{1}{6}$ of the time.

Assuming that three types of bird calls are independent Poisson processes, identify the distributions of the following random variables: give the name of the distribution and its parameters.

$($a$)W$ is the time it takes you to hear a woodpecker call.

$($b$)R$ is the number of robin calls you hear over the course of an hour.

$($c$)T$ is the time it takes you to hear $10$ bird calls total.

$($d$)$ After you've heard $10$ bird calls total, $S$ is the number of sparrow calls you've heard.