Pre-Algebra Demystified

SOLUTION

The ratio statement is:

16 yards

3 costumes

The proportion is:

16 yards

3 costumes

¼

x yards

8 costumes

16

3

¼

x

8

16  8 ¼3x

128 ¼3x

128

3

¼

3 x

3

4223 yards¼x

Hence, 42^23 yards or 42:6 yards should be purchased.

PRACTICE

1. If 5 pounds of grass seed will cover 1025 square feet, how many square
   feet can be covered by 15 pounds of grass seed?


2. If a homeowner pays $8000 a year in taxes for a house valued at
   $250,000, how much would a homeowner pay in yearly taxes on a
   house valued at $175,000?


3. If a person earns $2340 in 6 weeks, how much can the person earn in
   13 weeks at the same rate of pay?


4. If 3 gallons of waterproofing solution can cover 360 square feet of
   decking, how much solution will be needed to cover a deck that is 2520
   square feet in size?


5. A recipe for 4 servings requires 6 tablespoons of shortening. If the chef
   wants to make enough for 9 servings, how many tablespoons of short-
   ening are needed?

ANSWERS

1. 3075 square feet


2. $5600


3. $5070


4. 21 gallons


5. 13^12 or 13.5 tablespoons

158 CHAPTER 8 Ratio and Proportion