Correct Answer - Option 3 : 145 m
Given
According to the question, when A covers the distance of 200 metes
B covers only 200 - 20 = 180 meters
Again, in 100 meter race, B beats C by 5 meters.
Hence, if B runs 100 metres, C runs 100 - 5 = 95 metres
Calculation
∵ If B runs 100 m, C runs = 95 m
∴ If B runs 180 m, C runs = (95/100)× 180
C runs = 171 m
∴ A : B : C = 200 : 180 : 171
Hence, A will beat C by = 200 - 171
A will beat C = 29 m in 200 m race.
i.e. 29 × 5 = 145 m in 1 km race.