GRE General TestQuantitative ReasoningEasy
A farmer is fencing a rectangular plot of land. The length of the plot is 20 meters, and the width is 15 meters. If fencing costs $5 per meter, what is the total cost to fence the entire plot?
- A$750
- B$1500
- C$350
- D$175
Show answer & explanationAnswer & explanation
Correct answer: C. $350
The perimeter of a rectangle is calculated as 2 * (length + width). So, the perimeter is 2 * (20 + 15) = 2 * 35 = 70 meters. The total cost is the perimeter multiplied by the cost per meter: 70 meters * $5/meter = $350.
Why the other options are wrong
- A. This is the area (20*15) multiplied by the cost per meter, which is incorrect.
- B. This is the area multiplied by the cost per meter and then by 5, which is incorrect.
- D. This would be the cost if only one length and one width were fenced, which is incorrect.
Perimeter of a Rectangle
The perimeter of a rectangle is the total distance around its boundary, calculated by summing the lengths of all four sides.
- Formula: P = 2 * (length + width) or P = 2l + 2w.
- Units of perimeter are linear (e.g., meters, feet).
- Used for calculating fencing, borders, or pathways around a rectangular area.
Memory trick: Perimeter is 'around the edge', then multiply by the 'price tag'.