In a 180 m race. A covers the distance in 40 seconds and B in 45 seconds. In this race, A beats B by distance :

20 m

The correct answer is Option (2) → 20 m

Time taken by A = 40 s

Time taken by B = 15 s

Total Distance = 180 m

$\text{Speed}=\frac{\text{Distance}}{\text{Time}}$

$S_A=\frac{180}{40}=4.5m/s$

$S_B=\frac{180}{45}=4m/s$

Distance covered by B = Speed of B × Time taken by A

$=4×40=160m$

∴ Distance by which A beats B = 180 - 160 = 20 m