Page 495 - Basic College Mathematics with Early Integers

472 C HAPTE R 6 I PERCENT

Next, we solve for n.
#
n = 0.065 190 Write 6.5% as a decimal.
n = 12.35 Multiply.
a. The increase in licensed drivers was 12.35 million.
b. This means that the number of licensed drivers in 2007 was
Number of Number of Increase
licensed drivers = licensed drivers + in number of
in 2007 in 2000 licensed drivers
= 190 million + 12.35 million
= 202.35 million

Method 2. First we find the increase in licensed drivers.
In words: What number is 6.5% of 190?
('')''*
T T T
amount percent base
Translate: amount : a 6.5 ; percent
=
base : 190 100
Next, we solve for a.
#
#
a 100 = 190 6.5 Set cross products equal.
#
a 100 = 1235 Multiply.
#
a 100 1235
= Divide both sides by 100.
100 100
a = 12.35 Simplify.
a. The increase in licensed drivers was 12.35 million.
b. This means that the number of licensed drivers in 2007 was
Number of Number of Increase
licensed drivers = licensed drivers + in number of

in 2007 in 2000 licensed drivers
= 190 million + 12.35 million
= 202.35 million
Work Practice 4

Objective Finding Percent Increase and Percent Decrease

We often use percents to show how much an amount has increased or decreased.
Suppose that the population of a town is 10,000 people and then it increases by
2000 people.The percent of increase is
amount of increase : 2000
= 0.2 = 20%
original amount : 10,000
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In general, we have the following.

Percent of Increase

amount of increase
percent of increase =
original amount
Then write the quotient as a percent.