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

Answer: Option B

$$\begin{array}{rl}& \text{B runs}\frac{45}{2}\text{m in 6 sec}\\ & \therefore \text{B covers 300m in}\\ & =\left(6\times \frac{2}{45}\times 300\right)\sec \\ & =80\text{sec}\end{array}$$