How do I write the repeating decimal 0.47 as a fraction in simplest form

If the '47' is repeating, and the decimal is 0.474747 ...,

then it's equivalent to

47 / 99.

If it's just the '7' that repeats, and the decimal is 0.477777 ...,

then it's equivalent to

43 / 90.

Well first you have to know if the 7 is repeating, or if the 4 is repeating or if both are repeating, then you have to think, well actually since they are rational number you cannot do it, you have to get the exact number first.