2019 · Q79
A rectangular red carpet of size 6 ft × 12 ft has a dark red border 6 inches wide. What is the area of the dark red border?
Elementary MathematicsMensuration
- A9 square feet
- B15 square feet
- C17 square feet
- D18 square feet
Explanation
A 6-inch (0.5 ft) border leaves an inner carpet (6−1)×(12−1) = 5×11 = 55 sq ft. Border area = 6×12 − 55 = 17 sq ft.