The ratio of difference between area of a rectangle obtained in two cases,…
2023
The ratio of difference between area of a rectangle obtained in two cases, first when length of a rectangle is decreased by 4 cm and second when breadth of the original rectangle is increased by 4 cm to the area of rectangle is 4 : 9. Find ratio of numerical value perimeter to area of rectangle.
- A.
2 : 7
- B.
2 : 5
- C.
2 : 11
- D.
2 : 9
- E.
None of these
Attempted by 4 students.
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Correct answer: D
Let the rectangle be L by B. The two changed areas differ by 4L + 4B = 4(L+B). Given 4(L+B)/(LB) = 4/9, we get (L+B)/(LB) = 1/9. Therefore perimeter/area = 2(L+B)/(LB) = 2/9.