Question

er at the zoo surveyed 52 zoo visitors, asking them which animals they were scared of. The results were as follows: 20 visitors were scared of allieators, 21 visitors were scared of bears, 24 visitors were scared on heetahs, 33 visitors were scared of alligators or bears, 34 visitors were scared of bears or cheetans, were scared of alligators or cheetahs, and 5 visitors were scared of all three. (a) How many visitors were scared of none of these three animals? (b) How many visitors were scared of cheetahs but not bears or alligators? To get full credit for this problem, you must set up a Venn diagram and fill in each location with an appropriate number.

Answer 1

total visitor = 52. n (AnB nel= 5 N(A)= 20 (B) = 21 n(c)=3324 n (A) + (ANB) = n (B) - n (AB+ ACB) A or B = 20+21 - 33 n (Bne) = 21+24 -34 n (Anc)= 20+24 - 35 we know, NLAUBUC) = n(A) + n(B) + n(c) - n(ANB) - n(BNC) - n(ANC) + n(Anne) = 20+21+ 24-8-11-9 throne) + 5 HARDA 5 = 42 @ The number of visitor of none of these where scared animal is 52-42)=10. 6 visitor were scared of cheetah but not bears or alligetor = 24-11-9 +5 9.