Question 1179642
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1.the classroom is 20 feet long and 30 feet wide. the principal decided that the tiles would look attractive 
in that class. if each tile is 24 inches long and 36 inches wide, how many tiles are needed to fill the classroom?
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        In his post, @mananth solved this problem comparing the area of one single tile with the area of the classroom.


        Although in this case it leads to correct answer, nevertheless it is not a correct way to solve

        and to construct arguments.  In other words, his solution is badly designed.


        Below I place my correct and accurate solution.



<pre>
With the dimension of the room in one direction of 20 feet, 20/2 = 10 tiles can be placed in this direction.

With the dimension of the room in the other direction of 30 feet, 30/2 = 15 tiles can be placed in this direction.

Hence, 10 x 20 = 200 tiles are needed to cover the floor of the classroom.    <U>ANSWER</U>
</pre>

Now the problem is solved correctly and accurately.


Why it is necessary to look in each dimension separately ?


To guarantee that the integer number of tiles fits in each dimension.