In a 300 m race A beats B by 22.5 m or 6 seconds. B's time over the course is:

Solution (By Examveda Team)

$$\eqalign{ & {\text{B runs}}\frac{{45}}{2}{\text{m in 6 sec}} \cr & \therefore {\text{B covers 300m in}} \cr & = \left( {6 \times \frac{2}{{45}} \times 300} \right)\sec \cr & = 80\,{\text{sec}} \cr} $$