question_answer

A marginal walk all around the inside of an oblong piece of ground 40 m by 35 m occupies 650\[{{m}^{2}}\]. Find the width of the walk.

A) 3m                              

B) 4m

C) 5m                              

D) 6m

Correct Answer: C

Solution :

    Since the questions are of objective nature, the width of the park shall be given in the choice. If one of the choices be 5 meters, then it will satisfy the given condition. Shaded area\[=650\,{{m}^{2}}\] External area\[=40\times 35=1400\,{{m}^{2}}\] Internal area\[=(40-2\times 5)\,(35-2\times 5)\] \[=(30\times 25)\,{{m}^{2}}=750\,{{m}^{2}}\] \[\therefore \] Shaded are\[=\text{(}1400-750\text{)}\,{{m}^{2}}\] \[=650\,{{m}^{2}}\] Which is true. Hence, width of the walk is 5 m.