In a class of 100 students, every student has passed in one or more of the three subjects, i.e. History, Economics and English. Among all the students, 24 students have passed in English only, 14 students have passed in History only, 11 students have passed in both English and Economics only, and 12 students have passed in both English and History only. A total of 50 students have passed in History. If only 5 students have passed in all three subjects, then how many students have passed in Economics only?

15

Total number of students in the class =  100

Number of students who passed in English only = 24

Number of students who passed in history only = 14

Number of students who passed in both English and Economics only = 11

Number of students who passed in both English and history only = 11

Number of students who passed in history  = 50

Number of students who passed in all three subjects = 5

Number of students who passed in Economics only = 100 - (50+ 24 + 11) = 100 - 85 = 15