Digital SATMath: Problem-Solving and Data AnalysisMedium
A city council is reviewing a proposal for a new public park. The proposal states that 35% of the park's area will be dedicated to walking trails, 20% to a playground, and the remaining area to open green space. If the total area of the park is 150 acres, how many acres will be dedicated to open green space?
- A67.5 acres
- B22.5 acres
- C82.5 acres
- D30 acres
Show answer & explanationAnswer & explanation
Correct answer: A. 67.5 acres
First, calculate the total percentage dedicated to trails and playground (35% + 20% = 55%). Then, find the percentage for open green space (100% - 55% = 45%). Finally, calculate 45% of the total park area (0.45 * 150 = 67.5 acres).
Why the other options are wrong
- B. This is 15% of the total, which might result from an incorrect calculation of the remaining percentage.
- C. This is 55% of the total, the area for trails and playground, not the green space.
- D. This is 20% of the total, the area for the playground, not the green space.
Percentage of a Whole (Remaining Portion)
To find the remaining portion of a whole after several percentages have been allocated, subtract the sum of the allocated percentages from 100%. Then, calculate that remaining percentage of the total quantity.
- The sum of all parts of a whole is 100%.
- Convert percentages to decimals for calculations (e.g., 45% = 0.45).
- Multiply the decimal by the total quantity to find the part.
Memory trick: Portions accounted for, remaining space found.