He would have to sell at least 19 vacuums.
Answer:
Each car takes about 9 minutes to be washed.
Keywords:
<em>lines, plane, parallel
</em>
For this case we have five lines in a plane, and they ask us to find which of the four remaining lines is parallel to the line "r". We know that, by definition, two lines are parallel when they meet in the same plane, they maintain a certain distance between them, that is, if both prologue to infinity, they never intersect. Thus, the line parallel to line "r" must be line "s".
Answer:
The line parallel to the line "r" is the line "s"
