In a race of 1000 m, A can beat B by 100m. In a 400m, B beats C by 40 m. In a race of 500m. A will beat C by

Explanation:-

When A runs 1000 m, B runs 900 m.
Hence, when A runs 500 m, B runs 450 m.
Again, when B runs 400 m, C runs 360 m.
And, when B runs 450 m, C runs = 360 * ⁴⁵⁰/₄₀₀ = 405 m.
Required distance = 500 - 405 = 95 meter.
That means when A runs 500 meter then B can run 450m then C runs 405 m.