In a race of 800 meter, A can beat B by 40 meter. In a race of 500 meter, B can beat C by 5 meter. In a race of 200 meter, A will beat C by

In a 800 meter race, A covers 800 meter while B cover 760 meter.
∴ A covers 200 m while B will cover 760 x 200 / 800 = 190 m
Again, B covers 500 m while C 495 m
∴ B covers 190 m while C will cover = 495 x 190 / 500 = 188.10 m
Since, A covers 200 m while C 188.10 m
Hence, A will beat C by (200 – 188.10) = 11.9 m