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 2 of 8.
MAHESHKRISHNAN D said:
7 years ago
100*100 = 10000(1)
120*120 = 14400(2)
1-2 = 4400/100.
= 44%.
120*120 = 14400(2)
1-2 = 4400/100.
= 44%.
(3)
Harmanpreet said:
7 years ago
Each side 20% increased thus 120*120/100=144,
then 144-100 =44.
then 144-100 =44.
Puja said:
8 years ago
20 +20+20*20/100=44%.
Hussain said:
8 years ago
a*(200+a)/100.
so, 20*(200+20)/100.
=44%.
so, 20*(200+20)/100.
=44%.
ER RAJKUMAR ARYA said:
8 years ago
Let, l = b = 1 unit.
a1 = 1*1 = 1 sq.unit.
20% increase in both sides, new area a2 = 1.2*1.2 = 1.44.
i.e, % increase in area = 1.44 - 1 = .44 or 44%.
a1 = 1*1 = 1 sq.unit.
20% increase in both sides, new area a2 = 1.2*1.2 = 1.44.
i.e, % increase in area = 1.44 - 1 = .44 or 44%.
UDAY KINGS said:
8 years ago
Take side = a.
So, a increased by 20 so a = 120/100.
Area of square = a^2.
120/100*120/100 = 44.
So, a increased by 20 so a = 120/100.
Area of square = a^2.
120/100*120/100 = 44.
Veer said:
8 years ago
This can be solved in very simple steps. It is as follow.
The area of rectangle = l * b,
Consider initial is 100 and given that 20% increase,
100----->20%--->120----->20%---->144,
(144-100) = 44.
The area of rectangle = l * b,
Consider initial is 100 and given that 20% increase,
100----->20%--->120----->20%---->144,
(144-100) = 44.
Madhu said:
8 years ago
Increases 20% so (120/100) * (120/100) =14400/10000=144%.
44% increases.
44% increases.
Mero baduwal said:
8 years ago
Please solve the question that what percent changes in area of rectangular if there is mistake in length and breadth by one percent.
Mr.issue said:
8 years ago
Let original L and B=100 Increased L and B = 120,
Difference in Area = (120)2-(100)2,
(120+100)(120-100) = 4400.
Error In Length And Breath =
4400*100
------------- =44%.
100*100
Difference in Area = (120)2-(100)2,
(120+100)(120-100) = 4400.
Error In Length And Breath =
4400*100
------------- =44%.
100*100
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