The length of a rectangle is increased by 60%. By what percent would the width…
2019
The length of a rectangle is increased by 60%. By what percent would the width have to be decreased to maintain the same area?
- A.
50%
- B.
125%
- C.
75.5%
- D.
37.5%
Attempted by 1 students.
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Correct answer: D
Let the original length of the rectangle be L and width be W. Then, the original area is A = L × W.
When the length is increased by 60%, the new length becomes 1.6L.
Let the new width be W'. To maintain the same area, we have:
1.6L × W' = L × W
Dividing both sides by L: 1.6 × W' = W
So, W' = W / 1.6 = 0.625W
The decrease in width is:
W - 0.625W = 0.375W
Percentage decrease = (0.375W / W) × 100 = 37.5%
हिन्दी उत्तर:
मान लीजिए आयत की मूल लंबाई L और चौड़ाई W है। तब मूल क्षेत्रफल A = L × W है।
जब लंबाई में 60% की वृद्धि होती है, तो नई लंबाई 1.6L हो जाती है।
मान लीजिए नई चौड़ाई W' है। क्षेत्रफल को समान रखने के लिए, हमारे पास है:
1.6L × W' = L × W
दोनों तरफ L से भाग देने पर: 1.6 × W' = W
इसलिए, W' = W / 1.6 = 0.625W
चौड़ाई में कमी है:
W - 0.625W = 0.375W
प्रतिशत कमी = (0.375W / W) × 100 = 37.5%