GMAT Sample Questionbank - Mensuration
March 22, 2004
The area of a square field is 24200 sq m. How long will a lady take to cross the field diagonally at the rate of 6.6 km/hr?
| (A) | 3 minutes |
| (B) | 0.04 hours |
| (C) | 2 minutes |
| (D) | 2.4 minutes |
| (E) | 2 minutes 40 seconds |
Correct choice (C) Correct Answer (2 minutes)
Solution:
Let ‘a’ meters be the length of a side of the square field.
Therefore, its area = a2 square meters. --- (1)
We know that the length of the diagonal ‘d’ of a square whose side is ‘a’ meters =  a –-- (2)
From (1) and (2), we can deduce that the square of the diagonal = d2 = 2a2
Or d =  meters.
The time taken to cross a length of 220 meters while traveling at 6.6 kmph is given by
 (converting 1 km = 1000 meters and 1 hour = 60 minutes).
= 2 minutes
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