How to write body height in feet and inches?

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.

Julia bought 7 hats a week later half of all her hats were destroyed in a fire. there are now only 12 hats left with how many did she start

Hilary decided to purchase 3 points in order to lower her interest rate on her $140,000 mortgage. how much additional money does she need to bring to closing? a. $4200 b. $4000 c. $6 d. $400