Aptitude - Area - Discussion
Discussion Forum : Area - General Questions (Q.No. 4)
4.
The percentage increase in the area of a rectangle, if each of its sides is increased by 20% is:
Answer: Option
Explanation:
Let original length = x metres and original breadth = y metres.
Original area = (xy) m2.
| New length = |  |
120 | x |  m |
= | |
6 | x | m. |
| 100 | 5 |
| New breadth = | |
120 | y | m |
= | |
6 | y | m. |
| 100 | 5 |
| New Area = | |
6 | x x | 6 | y | m2 |
= | |
36 | xy | m2. |
| 5 | 5 | 25 |
The difference between the original area = xy and new-area 36/25 xy is
= (36/25)xy - xy
= xy(36/25 - 1)
= xy(11/25) or (11/25)xy
 Increase % = |
|
11 | xy x | 1 | x 100 | % |
= 44%. |
| 25 | xy |
Video Explanation: https://youtu.be/I3jLjLPn1W4
Discussion:
74 comments Page 8 of 8.
Kadhal said:
4 years ago
@All.
My Question is How they assume both l and b equal to 100, in rectangle l and b they never in equal size, right?
My Question is How they assume both l and b equal to 100, in rectangle l and b they never in equal size, right?
(10)
Omveer said:
3 years ago
Square Is also a Rectangle.
Assume both sides to be 100.
Actual Area = 10000.
With 20% increase in each side Area = 102*102=14400,Diffrence = 4400.
% Increase in Area = 4400/10000 * 100 = 44%.
Assume both sides to be 100.
Actual Area = 10000.
With 20% increase in each side Area = 102*102=14400,Diffrence = 4400.
% Increase in Area = 4400/10000 * 100 = 44%.
(13)
Akil said:
3 years ago
It is simple.
(1.2) L* (1.2) B = 1. 44 (L*B).
So, the total area increase is 44%.
(1.2) L* (1.2) B = 1. 44 (L*B).
So, the total area increase is 44%.
(18)
N G GANESH said:
3 weeks ago
In simple way:
Let's take;
Length l = 10.
Breadth b = 10.
=> l × b = 100
20% increase in side length means 20% of 10 is 2.
L = 12.
B = 12.
L×b = 12 × 12 = 144, which means 44% increase in area.
Let's take;
Length l = 10.
Breadth b = 10.
=> l × b = 100
20% increase in side length means 20% of 10 is 2.
L = 12.
B = 12.
L×b = 12 × 12 = 144, which means 44% increase in area.
(3)
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