A can run 22.5 m while B runs 25 m. In a kilometre race B beats A by:

Answer: Option A

$$\begin{array}{rl}& \text{When}\text{B}\text{runs}\text{25m,}\text{A}\text{runs}\frac{45}{2}m\\ & \text{When}\text{B}\text{runs}\text{1000m,}\text{A}\text{runs}\\ & =\left(\frac{45}{2}\times \frac{1}{25}\times 1000\right)m\\ & =900m\\ & \therefore \text{B}\text{beats}\text{A}\text{by}\text{100 m}\end{array}$$