How long will a packet sent from A to get to B take?

Assume host A generates $50$ packets instantly. How long will the first packet wait in A$$s queue before being transmitted? How long will the $50$th packet wait in A$$s queue before being transmitted? You can assume that no other packets are sent.

Suppose now that host A closed the previous connection and starts sending $300$ packets every $0\mathrm{.}1$s$.$ What is the throughput it achieves, assuming no packet losses?

If the transmission rate of the link between Y and Z changed to $10$ Mbps$.$ What is the maximum throughput that host A can achieve? If A tries to transmit packets at a higher rate, what will happen? Explain.