1. A bag of coins: A bag contains 30 coins, some dimes and some quarters. The total amount of money in the bag is $3.45. How many dimes and how many quarters are in the bag? 2. Drainage pipe slope:...

1. A bag of coins: A bag contains 30 coins, some dimes and some quarters. The total amount of money in the bag is $3.45. How many dimes and how many quarters are in the bag?

2. Drainage pipe slope: Suppose a drainage pipe slopes downward 6 inches for each 8-foot horizontal stretch. What is the slope of the pipe?