Why it is great than or equal to, for the equation inequality 2

This inequality represents the total passenger capacity. The problem states, "There are 12000 passengers to be moved." This means that the total number of passengers the buses can carry ($200x + 300y$) must be at least 12000 to ensure all passengers are transported. If it were less than 12000, some passengers would be left behind. Therefore, the total capacity must be greater than or equal to the required number of passengers.