Question

The length of a rectangle is twice of it's breadth. If the length of the rectangle is increased by 20% while it's breadth is decreased by 20% determine the % if any in its perimeter. ​

Answer 1

Answer:

Let the Breadth of Rectangle be 100, then Length of Rectangle be (2 × 100) = 200.

★ Perimeter of Rectangle :

↠ Perimeter = 2(Length + Breadth)

↠ Perimeter = 2(100 + 200)

↠ Perimeter = 2 × 300

↠ Perimeter = 600

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☢ According to the Question :

• New Length = 100 × 120/100 = 120
• New Breadth = 200 × 80/100 = 160

★ Perimeter of New Rectangle :

↠ New Perimeter = 2(Length + Breadth)

↠ New Perimeter = 2(120 + 160)

↠ New Perimeter = 2 × 280

↠ New Perimeter = 560

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☢ CHANGE PERCENTAGE :

⟶ Change% = (Old – New)/Old × 100

⟶ Change% = (600 – 560)/600 × 100

⟶ Change% = 40/6

⟶ Change% = 6.67%

∴ Change Percent in Perimeter is 6.67%.

Answer 2

change percent in pera meter is 6.67%