Pls answer this math question. In a given class 12 students have cats, 15 have dogs, and 6have both. There are nine students with no cat or dog. How many students are in the class? PLS ANSWER THE SAME QUESTION FOR 16 CAT STUDENTS, 10 DOG STUDENTS, 3 THAT HAVE BOTH, AND 12 STUDENTS HAVE NONE.

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.