What is the required number of bikes to initiate a bike-sharing service in New York City?

This interview question falls into the category of Fermi problems, which aim for a rough estimate based on sensible assumptions and straightforward calculations. The focus is not on obtaining a precise figure but rather on evaluating your critical thinking, problem-solving skills, and logical reasoning. To answer this question, you must make a series of informed guesses and assumptions. Important factors to take into account could include the population of New York City, the frequency of bike usage, and how a bike-sharing service operates.

To begin with, we need to estimate New York City's population, which is approximately 8 million people. For simplicity, let's consider that 1% of this population would utilize the bike-sharing service on a daily basis, equating to about 80,000 individuals. If we assume each bike is used by 4 different riders each day, we would require 20,000 bikes. Additionally, since these services generally maintain a buffer stock to accommodate repairs or high demand periods, we might add an extra 10%, resulting in a total of 22,000 bikes. This is a rough estimate, and actual figures could differ significantly based on the specific characteristics of NYC's biking culture and the objectives of the bike-sharing service.

If we consider that New York City's population is roughly 8 million, we can estimate that about 10% of the residents would regularly use the bike-sharing program, equating to 800,000 individuals. If we assume that each user only utilizes the service once a day, we would initially need 800,000 bikes. However, since each bike can be used multiple times daily, this figure can be reduced. If we project that each bike is used five times a day, we would require around 160,000 bikes. By adding an additional 10% for backups and maintenance, we arrive at approximately 176,000 bikes to launch a bike-sharing service in NYC. This is merely a preliminary estimate, and a comprehensive market analysis would be necessary for a more precise calculation.