Final answer:
The fraction 20/66 simplifies to 10/33 after dividing both the numerator and the denominator by the common factor of 2. Further simplification is not possible since 10 and 33 have no other common factors. Therefore, none of the provided options is the correctly simplified form of the fraction.
Step-by-step explanation:
The student has asked how to simplify the fraction 20/66. To simplify a fraction, one must find factors common to both the numerator and the denominator and divide them both by this common factor. In the case of 20/66, both numbers share a common factor of 2. Dividing both numerator and denominator by 2, we get 10/33. But we can simplify further because 10 and 33 also share a common factor of 10, which means we can divide both of them by 10 once more. This step simplifies to 1/3.3, which is not in our answer choices. However, reconsidering the factors, since 10 is 2 times 5 and 33 is 3 times 11, we should have divided by the common factor of 2 directly to get 10/33. We cannot simplify 10/33 any further because 10 and 33 have no other common factors. So the correct answer among the options is not reachable with a correct simplification. It appears there might be a mistake either in the calculation or the list of provided options.