If 1/3 of a sum of money is $21 what is the sum of the money

Acoin bank containing only dimes and quarters has 12 more dimes than quarters. the total value of the coins is $11. how many quarters and dimes are in the coin bank?

What is the image of c for a 90° counterclockwise rotation about a? (3, 7) (-1, 3) (7, 3)

Novak gives 9 packs of paper to a group of 5 students. if the group shares the paper equally how many packs of paper does each student get. write the a answer as a mixed number