The following are the results of a survey conducted on a small cross-section of students from the Symbiosis Group of institutes, to determine the readership of three magazines: Business India, Outlook and India Today. This survey was conducted in December 2006.
Number of students who read only Business India = 40
Number of students who read only Outlook = 60
Number of students who read only India Today = 110
Number of students who read all three magazines = 30
Number of students who read Business India and India Today, but not Outlook = 20
Number of students who read Business India and Outlook, but not India Today = 50
Number of students who read Outlook and India Today, but not Business India = 40
What was the total number of students surveyed?