In a study about a pandemic, data of 900 persons was collected. It was found that 190 persons had symptom of fever, 220 persons had symptom of cough, 220 persons had symptom of breathing problem, 330 persons had symptom of fever or cough or both, 350 persons had symptom of cough or breathing problem or both, 340 persons had symptom of fever or breathing problem or both, 30 persons had all three symptoms (fever, cough

Step-by-step solution

We denote the set of people having symptoms of fever, cough and breathing problem by F , C and B respectively Given that n F = 190 ,   n B = 220 and n C = 220 Also given, n F ∪ C = 330 ,   n B ∪ C = 350 , n F ∪ B = 340 and n F ∩ C ∩ B = 30 So n F ∩ C = n F + n C - n F ∪ C = 80 Similarly, n F ∩ B = n F + n B - n F ∪ B = 70 and n C ∩ B = n C + n B - n B ∪ C = 90 Putting the data in Venn diagram Number of people having at most one symptom = Nu