<span>He has 45 dollars. He needs 315 dollars in order for him to have 315 dollars he would to need to save what? Then take 315-45= 270 dollars. Therefore he would need to save 270 dollars.
Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions. </span>
Tony has 24 books in total because if 1/8 of the books are mystery and there are 8 mystery books you have to multiple the denominator by the amount of mystery books (8*3=24).