# Two man start together to walk a certain distance, one at 4 km/hr and another at 3 km/hr. The former arrives half an hour before the latter. Find the distance.

Two man start together to walk a certain distance, one at 4 km/hr and another at 3 km/hr. The former arrives half an hour before the latter. Find the distance.
[A]6 km
[B]7 km
[C]8 km
[D]9 km

6 km
If the required distance be x km, then
$\frac{x}{3} - \frac{x}{4} = \frac{1}{2}$
$=> \frac{4x-3x}{12} = \frac{1}{2}$
$=> \frac{x}{12} = \frac{1}{2}$
$=> x = 6 km$
Hence option [A] is correct answer.