Do not let the numbers confuse you when you want to answer this question. You have to focus on the prime meridian. Where is the prime meridian located? It is at 0 Degrees Longitude. This means that the distance of both Mike and Shirley are the same. They are just in different locations.
Take note that the longitude, latitude, and the prime meridian are considered to be imaginary lines. They do not exist when you look at the earth as a whole but it helps in determining the distance and the exact location not only of people but also the different countries and places that are situated all over the globe.