Ann's and Deb's astronomy classes are going on a field trip to see the night sky. Ann's class has 9 telescopes for 21 students. Deb's class has 12 telescopes for 28 students. Which class has the greater ratio of telescopes to students?

Noor brought 21 sheets of stickers. she gave 1/3 of a sheet to each of the 45 students at recess. she wants to give teachers 1 1/2 sheets each.

Ling listed all of the factors of a mystery number: 1,2,4,8,16,32 what is the mystery number?

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.