[tex]\frac{1}{3}[/tex]
Explanation
Probability is simply how likely something is to happen. Probability of event to happen P(E) = Number of favourable outcomes/Total Number of outcomes.
[tex]P=\frac{favorable\text{ outcomes}}{\text{total outcomes}}[/tex]
so
Step 1
Let
Number of studenst tha have a dog, given the do ot have a cat
=9
so
[tex]\text{Favorable ourcomes=9}[/tex]
and
total students = 3+9+2+13=27
so
[tex]\text{total outcomes = 27}[/tex]
finally, replace
[tex]\begin{gathered} P=\frac{favorable\text{ outcomes}}{\text{total outcomes}} \\ P=\frac{9}{27} \\ P=\frac{1}{3} \end{gathered}[/tex]
therefore, the answer is
[tex]\frac{1}{3}[/tex]
I hope this helps you