
Sweetwater High (home of the Red Devils, and one hell of a football team) held honors for 81 of their top students in the class of 1999. Most of the students who were honored were in the same classes together and knew each other very well. Of the honored students, 43 were taking English, 32 were taking Math and 41 were taking Science. There were 11 students taking both English and Math. Twentyone were taking both English and Science, and 16 were taking both Math and Science. Four students were taking only English and Math.
From the above description, can you determine how many students were taking:

