Question

X moves at a speed of 65km/hrs while Y who is behind X moves at a speed of 80km/hrs. What is the relative velocity of X with respect to X​

Answer 1

The relative velocity of X with respect to X is zero, as X can not move with respect to itself. However, if the question was asking for the relative velocity of Y with respect to X, then it would be calculated by subtracting the speed of X from the speed of Y, which would be 15km/hrs.