Answer:
9 students have pets
Step-by-step explanation:
From the above question, we are given the following information
Total number of students = 30
Let Pet Dog = D
Pet Cat = C
Pet Fish = F
Number is students that have pet dog
(D) = 10 students
Number of students that have pet cat (C) = 13 students
Number of students that have pet fish (F) = 7 students
Number of students that have Pet dog and cat ( D and C) = 4 students
Number of students that have Pet cat and fish (C and F) = 6 students
Number of student that has pet dog and pet fish (D and F) = 2 students
1 student has all three = ( D and F and C)
Number of student that have a pet Dog only
= n(D) - [n( D and C) + n( D and F) - n(D and C and F)]
= 10 -( 4+ 2 -1)
= 10 - 5
= 5
Number of student that have Pet cat only
= n(C) -[ n( D and C) + n( C and F) - n( D and C and F)]
= 13 -( 4 + 6 - 1)
= 13 - 9
= 4
Number is student that have a pet fish only
= n(F) - [n (C and F) + n( D and F) - n( D and C and F)]
= 7 - [6 + 2 - 1]
= 7 - 7
= 0
The number of students that have pets is calculated as:
(Number of students that have dogs only + Number of student that have cats only + Number of students that have fish only)
= 5 + 4 + 0
= 9
Therefore only 9 students have pets.
