The correct answer to the question “What latitude has the plane reached” if “an airplane takes off from a location at 17 S latitude and flies to a new location 55 due north of its starting point” is 38 degrees north (2). The answer is fairly simple to explain. We all know that the equator is 0 degrees, and we should take that into account if the airplane has crossed the equator.

Now, we should assign the latitude south as a negative value. In this scenario, we can assume that the airplane started at -17 degrees. So, if the airplane flew 55 degrees north, then it would just mean that the latitude is 55 degrees minus 17 degrees. Using that formula, we will get the answer: 38 degrees North.