A small shipping company (let's call it Trusk) transports its clients' inventory from China to the US. Suppose the average shipping times from China to the US, and from the US to China are both 30 days. Pre-COVID-19, when the time for loading containers in China and unloading them in the US was negligible (i.e., 0 days), Trusk transported 3,000 containers per month from China to the US. Following COVID-19 pandemic, due to labor shortage, the time to load containers in China, and time to unload containers in the US, both increased to 7.5 days. (Assume 1 month = 30 day, and that containers are shipped empty from the US to China). If Trusk continues to own the same number of containers and the shipping times do not change, how many containers Trusk transports from China to the US per month following COVID-19