**Question: **A certain port, cargo on large ships is transferred to a pier using a smaller craft, which cycles back and forth between the ship and the store. The time between arrivals of the smaller craft at the pier has an:

Exponential distribution

Mean: 25 mins.

Suppose there is only one unloading zone at the pier available for the small craft to use. If a craft docks at 9 a.m. and doesn’t finish unloading until 9:20 a.m., what is the probability that a second craft will arrive during this time at the unloading zone and have to wait before docking?