Q21 of 97 Page 780

The area of a square field is 8 hectares. How long would a man take to cross it diagonally by walking at the rate of 4 km per hour?

Given:


Area = 8 hectares = 0.08 km2


Speed = 4 km per hr



Let the side of square be s


Area of square = 1/2 × Diagonal2


⇒ 0.08 = 1/2 × Diagonal2


⇒ Diagonal2 = 2 × 0.08


⇒ Diagonal2 = 0.16


⇒ Diagonal= 0.04 km




= 0.01 hr


= (0.01 × 60) mins


= 6 mins


Therefore,


Time taken = 6 mins


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