Simplify. \[ \frac{27 x^{2} y^{4}}{9 x^{3} y^{5}} \]

Step 1 ：Given the expression \(\frac{27 x^{2} y^{4}}{9 x^{3} y^{5}}\)

Step 2 ：Divide the coefficients 27 and 9 to get 3

Step 3 ：Subtract the exponents of x, \(2 - 3 = -1\)

Step 4 ：Subtract the exponents of y, \(4 - 5 = -1\)

Step 5 ：The simplified form of the expression is \(3x^{-1}y^{-1}\)

Step 6 ：This can also be written as \(\frac{3}{xy}\)

Step 7 ：Final Answer: \(\boxed{\frac{3}{xy}}\)