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?
সমাধান
সঠিক উত্তর: Option B
Suppose, Breadth is x cm; length will be 2x cm
so area = 2x2
If its length is decreased by 5 cm it will be 2x-5 and breadth is increased by 5 cm it will be x+5
New area will be (2x-5)(x+5) =2x2+ 10x - 5x - 25= 2x2+ 5x -25
So,
2x2+ 5x - 2x2 = 75
5x = 75
x = 13
Length is 26cm
