How many people completed the survey form | UGC NET

UGC NET 2018 : 

A survey has been conducted on methods of  commuter travel. Each respondent was asked  to check Bus, Train or Automobile as a major  method of travelling to work. More than one  answer was permitted. 
The results reported  were as follows:  
Bus 30 people; 
Train 35 people; 
Automobile  100 people; 
Bus and Train 15 people; 
Bus and  Automobile 15 people, 
Train and Automobile  20 people; 
and all the tree methods 5 people.  
How many people completed the survey form? 

(a) 115 
(b) 120  
(c) 165 
(d) 160 

Solution:


5+15+5+10+70+10+5 = 120