Aptitude - Area - Discussion
Discussion Forum : Area - General Questions (Q.No. 3)
3.
The ratio between the perimeter and the breadth of a rectangle is 5 : 1. If the area of the rectangle is 216 sq. cm, what is the length of the rectangle?
Answer: Option
Explanation:
| 2(l + b) | = | 5 |
| b | 1 |
2l + 2b = 5b
3b = 2l
| b = | 2 | l |
| 3 |
Then, Area = 216 cm2
l x b = 216
| l x |
2 | l | = 216 |
| 3 |
l2 = 324
l = 18 cm.
Discussion:
22 comments Page 2 of 3.
Abi said:
8 years ago
2(5x+x)=216,
12x=216,
x=18.
12x=216,
x=18.
Ramana said:
9 years ago
Not understanding. Please explain me.
Shona said:
9 years ago
Please explain in simple method.
KARTIK said:
9 years ago
How can 2 (l + b)/b we let as = 5/1?
Ujjwal Mondal said:
9 years ago
I cannot understand it. Please solve it by a simple rule.
Sravani said:
1 decade ago
Ratio is given in terms of perimeter and breath i.e, 5:1.
Let length be 'l' and breadth be 'b'.
Perimeter = 2 (l+b).
Breadth = b.
So (perimeter/breadth) = 5:1.
(2(l+b)/b) = 5:1.
I think you got?
Let length be 'l' and breadth be 'b'.
Perimeter = 2 (l+b).
Breadth = b.
So (perimeter/breadth) = 5:1.
(2(l+b)/b) = 5:1.
I think you got?
Sajid said:
1 decade ago
2(l+b)/b.
Please explain why divided b?
Please explain why divided b?
Engr. Md. Easir Arafat said:
1 decade ago
Let the breadth to be x and the length to be y.
Hence, perimeter becomes 5x.
Now, 5x = 2(x+y).
Or, 3x = 2y -----------1.
Again, x*y = 216.
Or, x = 648/y ----------2.
Putting the value of x in eq. no. 1, we get,
648/y = 2y.
Or (2y*y) = 648.
Or y = Sqrt 324 = 18 cm.
Hence, perimeter becomes 5x.
Now, 5x = 2(x+y).
Or, 3x = 2y -----------1.
Again, x*y = 216.
Or, x = 648/y ----------2.
Putting the value of x in eq. no. 1, we get,
648/y = 2y.
Or (2y*y) = 648.
Or y = Sqrt 324 = 18 cm.
Muthulakshmi said:
1 decade ago
@Bharathi
your ans is correct .12 is not the length it is the value of breath.
see your explanation.
perimeter=2(l+b)
ratio b/w perimeter and breathis 5:1
5x=2(l+x)=2l+2x=>"l=3x/2",
area =3x*x/2=21=>x=12 which is not the value of length
substitute the value of "x" in the equation L=3x/2=(3*12)/2=18
ARE U CLEAR ?
your ans is correct .12 is not the length it is the value of breath.
see your explanation.
perimeter=2(l+b)
ratio b/w perimeter and breathis 5:1
5x=2(l+x)=2l+2x=>"l=3x/2",
area =3x*x/2=21=>x=12 which is not the value of length
substitute the value of "x" in the equation L=3x/2=(3*12)/2=18
ARE U CLEAR ?
Shahid said:
1 decade ago
@Bharathi ..your answer is absolutely right.
There is no error in it.
There is no error in it.
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