GED Mathematical Reasoning TestQuantitative Problem Solving with Rational NumbersEasy
A painter estimates that he can cover 320 square feet with 1 gallon of paint. If he needs to paint a wall that is 14 feet high and 24 feet long, how many gallons of paint will he need to purchase? Round your answer to the nearest whole gallon.
- A1 gallon
- B4 gallons
- C3 gallons
- D2 gallons
Show answer & explanationAnswer & explanation
Correct answer: D. 2 gallons
First, calculate the area of the wall. Then, divide the total area by the coverage rate per gallon to find the total gallons needed. Finally, round up to the nearest whole gallon since paint is sold in whole units.
Why the other options are wrong
- A. This option is incorrect; it underestimates the required paint, likely from an error in area calculation or rounding down.
- B. This option is incorrect; it significantly overestimates the paint needed, indicating a substantial calculation error.
- C. This option is incorrect; it overestimates the paint needed, possibly due to an arithmetic error or rounding up too aggressively.
Area Calculation & Unit Conversion
Area calculation determines the total surface within a 2D shape. Unit conversion adjusts quantities between different units of measurement.
- Area of a rectangle = length × width.
- Real-world problems often require rounding up to ensure sufficient quantity.
- Ensure units are consistent before performing calculations.
Memory trick: Always paint the wall, then divide by coverage, and always round up!