Algebra Demystified 2nd Ed

228 algebra De mystif ieD

Let x = 1st class price on January 1, 1995

$0.44 is 37.5% more than this quantity.

0440375

0441 0 375

0441 0 375

..

..

.(.)

=+

=⋅+

=+

xx

xx

x (factor)x

x

x

x

0441375

044

1 375

032

..

.

.

.

=

=

=

The price of a first-class stamp on January 1, 1995 was $0.32.

PRACTICE

1. A local cable television company currently charges $75 per month. It
   plans an increase in its monthly charge by 15%. What will the new
   rate be?


2. In 1970, U.S. energy consumption was 67.84 quad BTUs. In the year
   2008, the consumption had increased by 46.4%. What was energy con-
   sumption by the United States in the year 2008?


3. In 2008, the United States consumed 510 trillion BTUs of wind energy,
   which represents a 183% increase of wind energy consumed in the year
   2005. How much wind energy was consumed in the United States in the
   year 2005?


4. A worker’s take-home pay was $480 after deductions totaling 40%.
   What is the worker’s gross pay?


5. A cereal company advertises that its 16-ounce cereal represents 25%
   more than before. What is the original amount?


6. A couple does not wish to spend more than $45 for dinner at their
   favorite restaurant. If a sales tax of 721 % is added to the bill and they
   plan to tip 15% after the tax is added, what is the most they can spend
   for the meal?


7. A discount store prices some name brand toothpaste by raising the
   wholesale price by 40% and then adding $0.20. What must the tooth-
   paste’s wholesale price be if it sells for $3.00?

PRACTICE

1. A local cable television company currently charges $75 per month. It