What is the number of drones required to deliver all of FedEx's packages in the United States?

This question requires you to employ estimation and reasoning to address a hypothetical situation: determining how many drones would be necessary to deliver all of FedEx's packages in the United States. There isn't a definitive or publicly available answer to this question; rather, it provides an opportunity for you to showcase your problem-solving abilities by making informed assumptions to arrive at a rough estimate. The interviewer is interested in understanding your approach to problem-solving and how effectively and logically you can decompose and manage a complex challenge. Here are several important factors to consider in your response: Drone Capacity: Estimate the weight or dimensions of packages that an average delivery drone can carry. Volume of FedEx Packages: Estimate the average number of packages that FedEx handles each day. Daily Delivery Capacity of Drones: Determine how many deliveries a drone can complete in a day, taking into account factors like flying speed, battery life, and charging time. Keep in mind that your assumptions don't have to be perfectly accurate. The main objective is to demonstrate your reasoning and thought process in addressing the problem, rather than arriving at an exact figure.

Drones come in various sizes and capacities, but for the sake of this example, let's consider that an average delivery drone can carry 5 kg per delivery. If we take into account that the typical package weight for FedEx is around 2 kg, we can estimate that each drone could deliver 2 packages in one trip. Next, we should estimate the total number of packages that FedEx processes daily. As per their annual report, FedEx delivers approximately 15 million packages each day. If we assume that a drone can complete 10 trips in a day, taking into consideration factors like speed, battery life, and charging time, this means that each drone could deliver 20 packages daily. With these assumptions in mind, dividing 15 million packages by 20 packages per drone indicates that approximately 750,000 drones would be necessary to deliver all the packages handled by FedEx in a single day.

Given that a drone of reasonable size can transport a 5 kg package, and considering the average weight of a FedEx package is around 1.5 kg, a drone could feasibly carry three packages on each trip. Let's assume FedEx processes 16 million packages each day. If we take into account that a drone can operate for 4 hours daily, factoring in charging times and existing regulations on drone flight durations, and if each trip—which includes loading, travel, and unloading—lasts about 30 minutes, then a drone can complete roughly 8 trips in a day, translating to 24 packages delivered per drone daily. Therefore, by dividing the 16 million packages by 24, we would require approximately 666,666 drones to manage all FedEx deliveries in a single day.