When writing a repeating decimal as a fraction, why does the fraction always have only 9s or 9s and 0s as digits in the denominator

The table shows the webster family’s monthly expenses for the first three months of the year. they are $2,687.44, $2,613.09, and $2,808.64. what is the average monthly expenditure for all expenses?

Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?

Can someone me with my math problem pls my teacher is on my back about this