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If the length of a rectangle is increase...

If the length of a rectangle is increased by 25% and the width is decreased by 20%, then the area of the rectangle :

A

increases by 5%

B

decreases by 5%

C

remains unchanged

D

increases by 10%

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AI Generated Solution

The correct Answer is:
To solve the problem step by step, we need to analyze the changes in the dimensions of the rectangle and how they affect the area. ### Step 1: Understand the initial dimensions Let the original length of the rectangle be \( L \) and the original width (or breadth) be \( W \). ### Step 2: Calculate the new dimensions - The length is increased by 25%. Therefore, the new length \( L' \) can be calculated as: \[ L' = L + 0.25L = 1.25L \] - The width is decreased by 20%. Therefore, the new width \( W' \) can be calculated as: \[ W' = W - 0.20W = 0.80W \] ### Step 3: Calculate the original area The original area \( A \) of the rectangle is given by: \[ A = L \times W \] ### Step 4: Calculate the new area The new area \( A' \) of the rectangle after the changes is: \[ A' = L' \times W' = (1.25L) \times (0.80W) \] \[ A' = 1.25 \times 0.80 \times L \times W \] \[ A' = 1.00 \times L \times W \] \[ A' = A \] ### Step 5: Determine the change in area The change in area can be calculated as: \[ \text{Change in Area} = A' - A = A - A = 0 \] ### Conclusion The area of the rectangle remains unchanged after the changes in length and width. ### Final Answer The area of the rectangle does not change, which means the percentage change in area is 0%. ---
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