Percentage questions on the GED Math test will generally ask you to compare different quantities. In the following practice questions, you're asked to calculate a percentage change over time, and then to calculate a percentage of a total amount.

Practice Questions

  1. A plane has a seating capacity of 160 passengers, 40 in first class and the rest in economy class. The average first-class ticket costs $1,200, and the average ticket in economy class is $400. The price of each first-class ticket used to be $1,500. What percent decrease does the current price represent?

    A. 20% B. 25% C. 75% D. 80%

    The next question is based on the following information.

    The details of Janet's paycheck are shown here.


  2. What percentage of her gross salary does Janet pay toward Social Security? Round your answer to the nearest tenth of a percent.

    A. 0.03% B. 2.7% C. 0.3% D. 26.7%

Answers and Explanations

  1. The correct answer is A.

    Calculate the percent decrease as follows:


    Substituting in the new and old prices of the ticket gives you


    Hence, Choice (A) is the correct answer.

  2. The correct answer is B.

    Divide the amount spent on Social Security by the gross salary and multiply by 100:


    Rounding the nearest tenth of a percent gives you 2.7%, so Choice (B) is correct.

About This Article

This article is from the book:

About the book author:

Stuart Donnelly, PhD, earned his doctorate in mathe-matics from Oxford University at the age of 25. Since then, he has established successful tutoring services in both Hong Kong and the United States and is considered by leading educators to be one of the most experienced and qualified private tutors in the country.

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