Answer:
See the answer below
Explanation:
The time Laura took to reach the post office would depend on the speed of cycling.
We know that;
speed = [tex]\frac{distance}{time}[/tex]
hence,
time = [tex]\frac{distance}{speed}[/tex]
Since the distance from Laura's house to the post office is 4 km, the equation becomes;
time = [tex]\frac{4}{speed}[/tex]
Just ensure that the speed is in km per hour, minute, or seconds in order to obtain the time in hours, minutes, or seconds respectively.