The area of a square field is 7201 sq m. How long will a lady take to cross the field diagonally at the rate of 2.4 km/hr?  Choose the correct choice from the following answers.
A) 2 min
B) 3 min
C) 4 min
D) 5 min
E) 6 min

Rationale: area of a square field = 7201 sq m let the side of square = a a ^ 2 = 7201 = > a = 84.86 diagonal = ( 2 ) ^ ( 1 / 2 ) * a = 1.414 * 84.86 = 120 speed of lady = 2.4 km / hour = 2400 m / hour = 40 m / min time taken by lady to cross the field diagonally = 120 / 40 = 3 min answer b
Answer: B