The total distance covered by the two buses is given as 786 kilometers.
So, we can write the equation: 3x + 3(x - 16) = 786
Simplifying the equation: 3x + 3x - 48 = 786 6x - 48 = 786 6x = 786 + 48 6x = 834 x = 834 / 6 x ≈ 139
Therefore, the rate of the faster bus is approximately 139 km/h, and the rate of the slower bus is 139 - 16 ≈ 123 km/h.