Aptitude - Area - Discussion
Discussion Forum : Area - General Questions (Q.No. 1)
1.
The ratio between the length and the breadth of a rectangular park is 3 : 2. If a man cycling along the boundary of the park at the speed of 12 km/hr completes one round in 8 minutes, then the area of the park (in sq. m) is:
Answer: Option
Explanation:
| Perimeter = Distance covered in 8 min. = |  |
12000 | x 8 |  m = 1600 m. |
| 60 |
Let length = 3x metres and breadth = 2x metres.
Then, 2(3x + 2x) = 1600 or x = 160.
Length = 480 m and Breadth = 320 m.
Area = (480 x 320) m2 = 153600 m2.
Discussion:
48 comments Page 2 of 5.
Krishnakumar said:
8 years ago
Perimeter of rectangle formula is 2(l+w).
l is lengtg
W is width
12km/ hr.
1km 1000m.
1 hr is 60 s.
So 12*1000/60 m/s.
l is lengtg
W is width
12km/ hr.
1km 1000m.
1 hr is 60 s.
So 12*1000/60 m/s.
Naman Jain said:
8 years ago
12 km /hr --> to convert into m/s
12*(1000/(60*60))?
But in answer its 12*(1000/60) how?
12*(1000/(60*60))?
But in answer its 12*(1000/60) how?
Mohan said:
8 years ago
Thanks for this explanation.
Satish said:
9 years ago
Anyone, please answer me. If any solution for this question without using any formula, like "perimeter" we are using above.
Aruna said:
9 years ago
Many thanks for this great explanation and session.
Naveen said:
9 years ago
I clearly understand your explanation, which is help full for all. Thank you.
Gayu said:
9 years ago
@all.
2(3x + 2y) =1600 is a parameter of the rectangle so it uses here.
2(3x + 2y) =1600 is a parameter of the rectangle so it uses here.
Mahendra chozhan said:
10 years ago
@Fijo.
We can use but you have to convert the given time also into seconds, (i.e) 8 mins to 8*60 = 480 sec. Since it is given as 8 mins and 12 km/hr, we are converting them into 12*1000 = 12000 m and 1 hr = 60 mins.
Now the formula to find the distance is Speed = Distance/Time.
Hence Distance = Speed*Time.
D = 12000/60*8 = 200*8 = 1600 m.
Let x be some value.
The ratios given are 3: 2, (i.e) length will be 3 times the 'x' value and the breadth will be 2 times the 'x' value.
The formula for perimeter is 2(l+b).
l = 3*x.
b = 2*x.
(i.e) 2(3x+2x) = 1600 which is already found is already found.
6x+ 4x = 1600.
10x = 1600.
x = 160.
Now substitute value of x in length.
(i.e) 3x = 3*160 = 480 m.
Substitute value of x in breadth.
(i.e) 2x = 2*x = 2*160 = 320.
Therefore we have length and breadth.
Hence area of a rectangle is l*b = 480*360 = 153600 meters is the answer.
We can use but you have to convert the given time also into seconds, (i.e) 8 mins to 8*60 = 480 sec. Since it is given as 8 mins and 12 km/hr, we are converting them into 12*1000 = 12000 m and 1 hr = 60 mins.
Now the formula to find the distance is Speed = Distance/Time.
Hence Distance = Speed*Time.
D = 12000/60*8 = 200*8 = 1600 m.
Let x be some value.
The ratios given are 3: 2, (i.e) length will be 3 times the 'x' value and the breadth will be 2 times the 'x' value.
The formula for perimeter is 2(l+b).
l = 3*x.
b = 2*x.
(i.e) 2(3x+2x) = 1600 which is already found is already found.
6x+ 4x = 1600.
10x = 1600.
x = 160.
Now substitute value of x in length.
(i.e) 3x = 3*160 = 480 m.
Substitute value of x in breadth.
(i.e) 2x = 2*x = 2*160 = 320.
Therefore we have length and breadth.
Hence area of a rectangle is l*b = 480*360 = 153600 meters is the answer.
(2)
Kritika said:
10 years ago
Perimeter of the park is actually the distance covered by the cyclist and hence we use the formula of distance, speed and time.
Fijo Francis said:
1 decade ago
Why we are not using 5/18 formula to convert into m/s?
Can any of you please explain me please ?
Can any of you please explain me please ?
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