0.76 or 76/100. Simply add 2 zeros to 6/10 to make it 60/100. That'll make the problem alot easier :).
Answer:
66 + 1 ( not fully shaded ) squares will be shaded.
66.67% region will be shaded
Step-by-step explanation:
It is given that Marks uses a grid to model percent equivalent of
.
Let us assume that Mark uses a model containing 100 grids.
Now, as the grids are divided into region equivalent to
i.e. it is divided into 3 parts.
Moreover, 2 out of those 3 parts will be shaded.
As, 
i.e.
=66.67%
So, it gives us that 66 squares in the grid will be fully shaded and one will not be fully shaded.
Hence, 66 + 1 ( not fully shaded ) squares will be shaded and in percent, 66.67% of the region will be shaded.
Answer:
(a) 
Step-by-step explanation:
The question is incomplete. (See comment for complete question).
From the completed question, we have:

--- number of pyramids
Required
An expression for the area of the base
The total base length of the pyramid represents the perimeter of the base.
And since the base is a square, then the following relationship exist.

Where L represents the length of each side.
This gives

Make L the subject

The area of the base is then calculated as:

