If a runner takes as much time in running 20 metres as the car takes in covering 50 metres. The distance covered by the runner during the time the car covers 1 km is :

Solution (By Examveda Team)

According to the question,
$$\eqalign{ & \therefore 50{\text{ m}} = {\text{20 m}} \cr & \therefore {\text{1m}} = \frac{{20}}{{50}}{\text{m}} \cr & \therefore {\text{1000 m}} = \left( {\frac{{20}}{{50}} \times 1000} \right){\text{ m}} \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 400{\text{ metres}} \cr} $$