A stack of one dozen cookies of diameter 5 in,.....

Question:
Solution:
If exactly 12 cookies fit into the cylindrical cylinder. Let the thickness of the cookie be t, then we have the following equation:
[tex]Volume\text{ cylinder = }12\text{ x volume }of\text{ cookie}[/tex]that is:
[tex]176.715\text{ = }12\text{ (}\pi\text{( }\frac{5}{2})^2t)[/tex]this is equivalent to:
[tex]75\pi t\text{ = }176.715[/tex]solving for t, we get:
[tex]t\text{ = }\frac{176.715}{75\pi}\text{ = 0.75}[/tex]so that, the correct answer is:
[tex]t\text{ = 0.75}[/tex]