Aptitude - Area - Discussion
Discussion Forum : Area - General Questions (Q.No. 12)
12.
The length of a rectangle is halved, while its breadth is tripled. What is the percentage change in area?
Answer: Option
Explanation:
Let original length = x and original breadth = y.
Original area = xy.
| New length = | x | . |
| 2 |
New breadth = 3y.
| New area = |  |
x | x 3y |  |
= | 3 | xy. |
| 2 | 2 |
 Increase % = |
|
1 | xy x | 1 | x 100 | % |
= 50%. |
| 2 | xy |
Discussion:
25 comments Page 2 of 3.
Anshu said:
1 decade ago
ORIGINAL
LENGTH = X
BREADTH = Y
AREA = XY
----------------------------
LENGHT = 0.5X
BREADTH = 3Y
AREA = 1.5XY
THERE WAS INCREASE OF O.5 XY
0.5XY / XY * 1OO = 50%
SHORT AND CRISP METHOD
LENGTH = X
BREADTH = Y
AREA = XY
----------------------------
LENGHT = 0.5X
BREADTH = 3Y
AREA = 1.5XY
THERE WAS INCREASE OF O.5 XY
0.5XY / XY * 1OO = 50%
SHORT AND CRISP METHOD
Naga said:
1 decade ago
Assume L = 100, B = 80, L*B = 8000, Given data half length so, -50 breadth-3s = 3*80 = 240.
50*240 = 12000, change percentage = 12000-8000/80 = 50.
50*240 = 12000, change percentage = 12000-8000/80 = 50.
Sanjoy Kanrar said:
1 decade ago
Let, length = 100 and breadth = 100.
New area:Previous area = {(100/2)*(100*3)}:{100*100}.
= 150:100.
So increase = 50%.
New area:Previous area = {(100/2)*(100*3)}:{100*100}.
= 150:100.
So increase = 50%.
(2)
Arun said:
1 decade ago
Hey sri wat kanmani told is right
see new area =3/2xy
orginal area=xy
so (3/2xy-xy)/xy=.50%(i.e)50%
see new area =3/2xy
orginal area=xy
so (3/2xy-xy)/xy=.50%(i.e)50%
Devender said:
1 decade ago
In the formula x+y+xy/100. Y value should be 300. How it is taken 200. I am not getting answer.
Akil said:
3 years ago
It is simple:
(L*1/2)(B*3),
LB*(3/2),
LB*(1.5).
So clearly, 50% increased.
(L*1/2)(B*3),
LB*(3/2),
LB*(1.5).
So clearly, 50% increased.
(2)
Sri said:
1 decade ago
Please explain in detail.
Isn't it.
New area/original area = (3/2xy) /xy.
Isn't it.
New area/original area = (3/2xy) /xy.
Khadar said:
5 years ago
By using this method:
-50+300+((-50)(300)/100),
100%.
-50+300+((-50)(300)/100),
100%.
Adilakshmi said:
1 decade ago
Please explain clearly what is the formula used.
Abc said:
1 decade ago
How to know the area increasing or decreasing ?
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