Let the distance be D km Speed of the 1st bus = D/5 km/hr Speed of the 2nd bus = (2 D)/5 km/hr Speed of 2nd bus = 2 × speed of 1st bus ∴ Distance travelled by 1st bus till 8:30 am = 2 × D/5 = (2 D)/5 Now, Distance between buses = D - (2 D)/5 = (3 D)/5 km Time taken = ((3 D)/5)/( D/5 + (2 D)/5 ) = 1 hour ∴ 8:30 am + 1 hour = 9:30 am