1.  How many liters of water must be added to 9 liters of a 40% solution of hydrochloric acid to make it a 30% solution?
2.  How many liters of water must be added to 26 liters of a 15%  antifreeze solution to dilute it to a 12% solution?
3.  Dr. Green has one solution that is 40% salt and another solution that is 65% salt.  How much of the 65% solution must be added to 5 deciliters of the original solution that is 55% salt?
4.  Pilar has 7 more nickels than dimes.  Their total value is \$1.55.  How many coins of each type does she have?
5.  The cost of a certain metal varies directly as its mass.  If 9 kg cost \$27, find the cost of 45 kg.
6.  Find three consecutive odd integers such that the square of the first is 16 more than the last.
7.  The ten digit of a two-digit number is 1 more than 4 times the units digit.  The sum of the number and the number with its digits reversed is 121.  Find the number.
8.  Five out of 12 people use a certain product.  How many people use this product in a town of 48,000.
9.  The length of a rectangle is 2 m less than 5 times the width.  The area is 39 m^2.  Find the length and the width.