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?	Pick one:  A) 3 minutes  B) 0.04 hours  C) 2 minutes  D) 2.4 minutes  E) 2 minutes 40 seconds
Explanatory Answer   Step 1: Compute the length of the diagonal of the square   Let 'a' meters be the length of a side of the square field.   Therefore, its area = a2 square meters. --- (1)   The length of the diagonal 'd' of a square whose side is 'a' meters = √2 a --- (2)   From (1) and (2), we can deduce that the square of the diagonal = d2 = 2a2 = 2(area of the square)   Or d = √2 * area meters.   d =√2∗24200=48400 = 220 m.   Step 2: Compute the time taken to cross the field   The time taken to cross a distance of 220 meters while traveling at 6.6 kmph = 220 m/6.6 kmph   Convert unit of speed from kmph to m/min   1 km = 1000 meters and 1 hour = 60 minutes. So, 6.6 kmph = 6.6∗1000/60 m/min = 110 m/min   ∴ time taken = 220/110= 
<gadget id="calculator">220/110</gadget>
<output>2</output>
2 minutes   2 minuteshoice 2 minutes
<result>C</result>
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?