Alfred has twelve coins in his piggy bank. Some of the coins are quarters, some are nickels, and he has a total of $3.15. Which system of equations can be used to determine how many quarters, x, and how many nickels, y, he has? Please don't answer unless you know the answer.

The table below shows the number of free throw shots attempted and the number of shots made for the five starting players on the basketball team during practice. each player's goal is to make 80% of her shots. players number of free throws made free throw attempts kelly 16 20 sarah 25 30 maggie 31 40 liz 44 50 kim 47 60 how many players made at least 80% of their shots? round to the nearest percent.