64 is 55% of what number

If 64 is 55% of a number, since 55%=0.55 (by dividing it by 100), we have 0.55*x=64. Dividing both sides by 0.55, we get 64/0.55=x=106+36/99=106+12/33 by dividing both the numerator and denominator by 3.

For repeating decimals, if it repeats every 2 digits, like 0.363636, we have (the digits that repeat) / 99

Feel free to ask any further questions!