Answer
$a)\ average\ velocity = 100\ km/hr$
$b)\ average\ velocity = 100\ km/hr$
$c)\ average\ velocity = 0\ km/hr$
$d)\ average\ velocity = -50\ km/hr$
Work Step by Step
We know that: $average\ velocity = \frac{total\ distance\ traveled}{total\ time}$
So we can substitute the values into the equation as follows:
$$a)\ average\ velocity = \frac{50-0}{0.5-0} = 100\ km/hr$$
$$b)\ average\ velocity = \frac{100-50}{1.0-0.5} = 100\ km/hr$$
$$c)\ average\ velocity = \frac{100-100}{1.5-1} = 0\ km/hr$$
$$a)\ average\ velocity = \frac{50-100}{2-1} = -50\ km/hr$$
