csateasy
A gardener increased the area of his rectangular garden by increasing its length by 40% and decreasing its width by 20%. The area of the new garden
- A.has increased by 20%.
- B.has increased by 12%.
- C.has increased by 8%.
- D.is exactly the same as the old area.
▶ Answer & Explanation
Correct answer: B. has increased by 12%.
Let the original length be L and the original width be W. The original area is A = L * W. The new length becomes L' = L * (1 + 40/100) = 1.4L. The new width becomes W' = W * (1 - 20/100) = 0.8W. The new area is A' = L' * W' = (1.4L) * (0.8W) = 1.12 * (L * W) = 1.12A. This represents an increase of 12% over the original area.
Source: UPSC csat 2014