The number of miles Michelle can ride her bike in a given amount of time is directly related to her average speed. If Michelle can ride her bike 5 miles in 20 minutes, how far can she ride her bike in 50 minutes? A. 7.5 miles

B. 10.5 miles

C. 12.5 miles

D. 15 miles

E. 20 miles ​

Factor this polynomial completely x^2-64

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.

Abicycle training wheel has a radius of 3 inches. the bicycle wheel has a radius of 10 inches.approximately how much smaller, in square inches and rounded to the nearest hundredth, is the area of the training wheel than the area of the regular wheel? *