$0.\overline{36}$ expressed in the form $\frac{p}{q}$ equals
Aptitude
Decimal Fraction
Difficulty: Easy
Choose an option
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A$\frac{4}{11}$
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B$\frac{4}{13}$
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C$\frac{35}{90}$
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D$\frac{35}{99}$
Answer
Correct Answer: $\frac{4}{11}$
Explanation
Concept & Formula
To express a pure recurring decimal in the form $\frac{p}{q}$, assign the repeating pattern as the numerator and place an equivalent number of $9$s as the denominator, then simplify the resulting fraction to its lowest terms.
$$ 0.\overline{xy} = \frac{xy}{99} $$
Step-by-Step Solution
Given the decimal expression: $0.\overline{36}$
The repeating part is $36$, which has two digits. We place $36$ over $99$.
$$ \frac{p}{q} = \frac{36}{99} $$
Next, simplify the fraction by dividing both the numerator and the denominator by their greatest common divisor, which is $9$.
Numerator: $\frac{36}{9} = 4$
Denominator: $\frac{99}{9} = 11$
$$ \frac{p}{q} = \frac{4}{11} $$
Exam Strategy & Shortcut
Recognize that $36$ and $99$ are both multiples of $9$. You can quickly mentally reduce $\frac{36}{99}$ by dividing by $9$ to arrive straight at $\frac{4}{11}$.
Common Pitfall
Students often stop at $\frac{36}{99}$ and panic when they don't see it in the options, or worse, they incorrectly guess a similar-looking option like $\frac{35}{99}$. Always remember to reduce your fraction to its simplest form.
Final Answer
Therefore, the correct answer is $\frac{4}{11}$.