The length of a rectangle is twice its breadth. If its length is decreased by 5 cm and breadth is increased by 5 cm, the area of the rectangle is increased by 75 sq.cm. Find the length of the rectangle?

The length of a rectangle is twice its breadth. If its length is decreased by 5 cm and breadth is increased by 5 cm, the area of the rectangle is increased by 75 sq.cm. Find the length of the rectangle? Correct Answer 20cm

Let the breadth of the given rectangle be x then length is 2x. thus area of the given rect is 2x2

 

 

 

after dec 5cm from length and inc 5cm breadth , new lenght becomes 2x-5 and breadth is x+5.thus new area =(2x-5)(x+5)=2x2+5x-25

since new area is 75 units greater than original area thus 2x2+75 = 2x+5x-25 5x=75+25 5x=100 therefore x=20 hence length of the rectangle is 40 cm.

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