Q16 of 99 Page 264

The cost of carpeting a big hall of length 18 meters is Rs. 2160. If the breadth of the floor would be 4 meter less, then the cost would have been Rs. 1,620. Let us calculate perimeter and area of the hall.

Let original length be L and breadth be B.


L = 18m. B = ?


Area = L × B = 18B


New length = 18m, new breadth = B - 4 m


New Area = 18(B - 4)


Let the rate be X per sqm.


Now, 18B × X = 2160


18(B - 4) × X = 1620


Dividing two equations,



1620B = 2160(B - 4)


B = 16m


Perimeter = 2(L + B) = 68m


Area = L × B = 16 × 18m2 = 288m2


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