There are 25 tiles total - triangles or squares - 84 edges
triangle (<em>t</em>) = 3 sides
square (<em>s</em>) = 4 sides
<em>t</em>+<em>s</em>= total tiles
<em><u>t</u></em><u>+</u><em><u>s</u></em><u> = 25 </u>← solve
3<em>t</em> + 4<em>s</em> = total sides
<u>3</u><em><u>t </u></em><u>+ 4</u><em><u>s</u></em><u> = 84</u> ← solve
<em>
</em><em>t </em>= 16 <em>s</em> = 9
Check
16 + 9 = 25
3(16) + 4(9) = 84
48 + 36 = 84
<u>There are 9 square tiles in the box</u>
First, let's convert the mixed fraction into an improper fraction:
2 3/8 = 21/8
21/8 * 400 = 8400/8
8400/8 = 1050
It will cover 1050 square ft.
A is the only correct choice
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