Aptitude - Area - Discussion

Discussion Forum : Area - General Questions (Q.No. 5)
5.
A rectangular park 60 m long and 40 m wide has two concrete crossroads running in the middle of the park and rest of the park has been used as a lawn. If the area of the lawn is 2109 sq. m, then what is the width of the road?
2.91 m
3 m
5.82 m
None of these
Answer: Option
Explanation:

Area of the park = (60 x 40) m2 = 2400 m2.

Area of the lawn = 2109 m2.

Area of the crossroads = (2400 - 2109) m2 = 291 m2.

Let the width of the road be x metres. Then,

60x + 40x - x2 = 291

x2 - 100x + 291 = 0

(x - 97)(x - 3) = 0

x = 3.

Video Explanation: https://youtu.be/R3CtrAKGxkc

Discussion:
75 comments Page 7 of 8.

Ashish Malviya said:   1 decade ago
Cosidering Road parallel to 60m side Area :- 60x.
Cosidering Road parallel to 40m side Area :- 40x.

Common area :- x*x.

Hence :- 291=60x+40x-x*x.

Koushik said:   1 decade ago
Excellent Ayoosh. Thank you very much.

Rupam said:   1 decade ago
There is no intercrossing left. When we considered 60x +40x, aren't we considering the intercrossing too? Otherwise the lengths couldn't have been 60 and 40.

SHARDUL said:   1 decade ago
Area of the park = (60 x 40) m2 = 2400 m2.

Area of the lawn = 2109 m2.

Area of the crossroads = (2400 - 2109) m2 = 291 m2.

Let the width of the road be x metres. Then,

60x + 40x - x2 = 291.

x2 - 100x + 291 = 0.

(x - 97)(x - 3) = 0.

x = 3.

Abhi said:   1 decade ago
Ayoosh explaination really helped me. Thanks Ayoosh :)

Peter said:   1 decade ago
@Rkbm your answer best answer.

Puskar prasun said:   1 decade ago
Guys! it should be 2x^2 instead of simply x^2? don't you all agree?

Saila said:   1 decade ago
@Puskar,

You may go through Diego's answer for better understanding.

Ankit said:   1 decade ago
Thanks prajwal.

ARAVIND said:   10 years ago
Great explanation @Ayoosh.


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