ATI TEAS (Test of Essential Academic Skills) Version 7MathematicsMedium
A patient's wound measured 12 cm by 5 cm initially. After two weeks, the wound measured 10 cm by 4 cm. What is the percentage decrease in the wound's area, to the nearest whole percent?
- A33%
- B25%
- C50%
- D16%
Show answer & explanationAnswer & explanation
Correct answer: A. 33%
Initial area = 12 cm * 5 cm = 60 cm². Final area = 10 cm * 4 cm = 40 cm². Decrease in area = 60 cm² - 40 cm² = 20 cm². Percentage decrease = (Decrease in area / Initial area) * 100 = (20 / 60) * 100 = (1/3) * 100 = 33.33...%. Rounded to the nearest whole percent, this is 33%.
Why the other options are wrong
- B. This could be a miscalculation, perhaps using an incorrect base for the percentage.
- C. This is an overestimation, possibly due to calculating the percentage of the final area instead of the decrease.
- D. This might be a calculation error or a misinterpretation of percentage decrease.
Percentage Decrease (Area)
The relative reduction in area, calculated as the decrease in area divided by the initial area, expressed as a percentage.
- Requires calculating initial and final areas.
- Formula: ((Initial Area - Final Area) / Initial Area) * 100.
- Used to track changes in size, such as wound healing or tissue shrinkage.
Memory trick: Initial minus Final, divided by Initial, then times 100.