Among 400 students, 51% study sociology, 46% study mathematics and 40% study biology. If 34% of students study both mathematics and sociology, what is the largest possible number of students who study biology but do not study either mathematics or sociology?
Choose the correct option:
A) 30
B) 90
C) 148
D) 172
E) 188

Rationale: i would just like to add a bit of explanation after the step where you calculate that the number of students studying both m and s = 136 using your analysis : we see that the total number of students who study either maths or sociology = 184 + 204 - 136 = 252 so , in the image we know that the number of students in the zone with the black boundary = 252 let ' s assume the number of students who studyonlybiology to beb ( this is the number that we have to maximize ) and , let ' s assume the number of students who study none of the three subjects , that is the number of students in the white space = w since the total number of students = 400 , we can write : 252 + b + w = 400 or , b + w = 400 - 252 = 148 that is , b = 148 - w so , the maximum value ofbwill happen forw = 0 this is how we get , the maximum value ofb = 148 c
Answer: C