This is for the first one :) sorry I don’t have time to do the other two, but this will help with the other ones
[(0.24*5)+ (0.66*5)] == 4.50
0.24x5 = 1.20
0.66x5 = 3.30
+ ____
4.50
27.00÷4.5 = 0.166666667
I showed the work for the first question in the image attached. For the second question, it's C
The number of triangles formed by connecting one of the vertices to the rest of the vertices is equal to n - 2. The answer is the first choice. As you may observed, for the quadrilateral, we can form 2 triangles. For pentagon, we may form 3 triangles.
The estimate could be 6.53