Fundamentals of Math

Fundamentals of Mathematics

3.6 Percent Change We can find the percentage by which something has increased or decreased. The percentage change can be found out by the following formula:

ℎ =

∗ 100%

For instance, Mrs. and Mr. Wilson purchased a property for $150,000 in the year 2010. It is now valued at $355,000. Calculate the percent increase.

In this case, the original cost would be $150,000 and the increase in the value would be the difference between both the amounts, that is $205,000 (355,000- 150,000). The percentage increase would be:

205000 150000

=

∗ 100% = 136.67%

Whenever the price falls, it shows percentage decrease, as in cases of depreciation of assets.

Practice 3.6

1. Usually, a chef uses 10 ounces of chocolate to make chocolate chip cookies. But he started using 14.2 ounces instead. He should advertise the cookies as having _____ percent more chocolate.

2. Caesar used to have $468.00 in his savings account, but after a year, the amount increased to $542.88. This was an increase of _____%.

3. In September, Bill spent 33 hours watching Netflix. In October, he only spent 27.72 hours watching. What was the percent decrease in the amount of time he spent watching Netflix?

Answer Key on Page 120

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