IXL | Percent of change: word problems

The depth of a lake in Washington changes over time due to rainfall and evaporation. A few months ago, the depth was 260 feet. Currently, the lake is 25% less deep. What is this year's depth?

feet

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question

Last semester, Mabel earned an average test score of 80 points on her math tests. This semester, her average score is 84 points. What is the percent of increase in Mabel's average test score?

key idea

percent of change

amount of change

original amount

solution

Plug 80 points and 84 points into the formula for percent of change and simplify.

percent of change

amount of change

original amount

–

0.05

Write the number as a percent.

0.05

The percent of increase in Mabel's average test score is 5%.

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Lesson: Percent change

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Not feeling ready yet? These can help:

H.10Percent of change

H.4Find what percent one number is of another: word problems

H.7Percents of numbers: word problems

Lesson: Percent change

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