Let D represent number of students that have dog
Let C represent number of students that have cat
n(U) = 360
n(D) = 193
n(C)= 160
Let n (D n C) be y
From the Venn diagram,
83 + 193-y + y+160-y = 360
436-y=360
-y = 360-436
-y = -76
y=76
Therefore, 76 students have both dogs and cat
Part two
Number of the students that have a cat but not a dog = 160-y
=160-76
=84
% of the students have a cat but not a dog = 84/360 x 100
=23.33%