What is the Domain of this linear function?

Tanyss's house has 25 windows. her brother has washed 22 of the windows. what percent of the windows has her brother washed?

In the next 10 month, colin wants to save $900 for his vacation. he plans to save $75 each of the first 8 months. how much must he save each of the last 2 months in order to meet his goal if he saves the same amount each month ?

Luigi is the first person to finish a 5k race and is standing 13 feet beyond the finish line. another runner, mario, is still running the race and has approximately 24 feet before he reaches the finish line. what is the distance between mario and luigi? explain through words, numbers or pictures how you found the answer.