To convert the repeating decimal \( 0.27\overline{27} \) to a rational number, we can use the following method:
Let \( x = 0.27\overline{27} \).
This means that \( x = 0.27272727\ldots \).
Since the decimal repeats every 2 digits, we can multiply \( x \) by 100 to shift the decimal point two places to the right:
\[ 100x = 27.27272727\ldots \]
Now, we have two equations:
- \( x = 0.27272727\ldots \)
- \( 100x = 27.27272727\ldots \)
Next, we subtract the first equation from the second:
\[ 100x - x = 27.27272727\ldots - 0.27272727\ldots \]
This simplifies to:
\[ 99x = 27 \]
Solving for \( x \):
\[ x = \frac{27}{99} \]
Now, we can simplify \( \frac{27}{99} \):
Both the numerator and denominator can be divided by 9:
\[ \frac{27 \div 9}{99 \div 9} = \frac{3}{11} \]
Thus, the rational number in simplest form is:
\[ \boxed{\frac{3}{11}} \]