In 18 years, jenny will be three times as old as she is now. how old is she?

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.

Pls yall i really need the answer fr fr

6cm10 cma conical paper cup has dimensions as shown in the diagram. how much water can the cup hold when full?