Please help me with this

If i have 20$ and i gave 5$ away how much i got

Which of the following is an example of a rational number? a. π b. √ 9 c. √ 8 d. 3.8362319

Will mark the brainliest.paula makes stained-glass windows and sells them to boutique stores. if her costs total $12,000 per year plus $4 per window for the frame. how many windows must she produce to earn a profit of at least $48,000 in one year if she sells the windows for $28 each?