The length of a room is 3 more than its breadth :

The length of a room is 3 more than its breadth. If the area of the floor of the room is 70 m2, then the perimeter of the floor will be

  1. 28 m
  2. 17 m
  3. 14 m
  4. 34 m
Anurag Mishra Professor Asked on 27th December 2015 in Maths.
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1 Answer(s)

Answer:  (4) 34 m 

Explanation:-
Let the breadth of a room be X m 

The length of a room is 3 more than its breadth. 
Then, the length of the room = (X + 3) cm 

If the area of the floor of the room = 70 cm^2
Then, X x (X + 3) = 70 
  X^2 + 3 X = 70 
X^2 + 3 X – 70 = 0 
X^2 + 10 X – 7 X – 70 = 0 
X (X + 10) – 7 (X + 10) = 0
(X – 7) (X + 10) = 0 
X – 7 = 0
X  = 7 

Thus, the breadth of the room is X = 7 m and the length of the room is X + 3 = 7 + 3 
 = 10 m 

So, the perimeter of the room = 2 (10 + 7)
 = 2 x 17
 = 34 m 

Hence, the correct answer is option (4) 34 m. 

Anurag Mishra Professor Answered on 27th December 2015.
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