This question is based on the data given below. In a class of 150 students, 45 take History, 65 take Geography and 10 take both History and Geopraphy.

How many students take at most one subject 

Solution:

Total number of students = 150

Number of students take history = 45

Number of students take Geography = 65

Number of students take both History and Geography = 10

Number of students take history only = 45 – 10 = 35

Number of students take geography only  one subject = 65 – 10=55

Number of students take at least one subject $=35+10+55=100$

Numbers of students do not take any one of the subject $=150-100=50$

Atmost one subject means  = One subject or less than one

                                                  = i.e.  [Total of students take both subjects]

                                                 $=150-10=140$