In a kilometre race, A beats B by 30 seconds and B beats C by 15 seconds. If A beats C by 180 metres, the time taken by A to run 1 kilometre is.

Answer: Option B

Let the time taken by A to cover 1 km = $$x$$ seconds
Time taken by B and C = $$x$$ + 30 seconds and $$x$$ + 45 seconds

$$\begin{array}{rl}& \frac{x}{x+45}=\frac{41}{50}\\ & 50x=41x+1845\\ & x=205\text{ seconds}\end{array}$$