Percent Increase and Decrease: TEAS Practice Question with Answer & Explanation

Understanding Percent Increase

To find the percentage increase between an original value and a new value, you must follow a specific two-step mathematical process. This is a common topic on the TEAS Math section, often appearing in the context of wages, medication dosages, or patient statistics.

Step 1: Find the Amount of Increase

First, subtract the original value from the new value to determine the actual dollar amount of the raise.

• New Value: $42.00
• Original Value: $35.00
• $42.00 - $35.00 = $7.00

Step 2: Calculate the Percentage

To find the percentage, divide the amount of increase by the original value. Many students make the mistake of dividing by the new value—always remember that the "starting point" is your divisor.

• Increase / Original = Decimal
• $7.00 / $35.00 = 0.2

Step 3: Convert to a Percentage

To convert a decimal to a percentage, multiply by 100 or move the decimal point two places to the right.

• 0.2 × 100 = 20%

Analysis of Incorrect Answers

• Choice A: 15% – This is an incorrect calculation likely resulting from a basic estimation error or dividing the increase by an incorrect number.
• Choice B: 18% – This is a common "distractor" value that does not correlate to the standard formula (Increase / Original).
• Choice D: 22% – This might be reached if a student accidentally adds the increase to the wrong base or performs the division incorrectly.

TEAS Concept: Ratios and Proportions

Percentage increase is a subset of the Numbers and Algebra category on the TEAS. It tests your ability to interpret changes in numerical data. The fundamental formula to memorize is: [ (New - Old) / Old ] × 100 = % Change.

Memory Tip for the Exam

Always remember: "Difference over Original." No matter how the numbers change, the denominator is always the starting (older) number. This will keep you from getting confused when numbers are large or similar.