A non-response bias is when subjects are selected to participate in a survey but some choose not to respond. This would lead to a portion of the population being misrepresented leading to inaccurate results. For example, those who returned the survey might be more likely to do something than those who did not complete the survey.
The reciprocal parent function would be, F(x)= 1/x
Recall your d = rt, distance = rate * time.
notice, the distance are the same, say it was "d" miles.
and if car A is travelling at a speed of say "r" mph, then B is going at "r+15" mph.

how far is B going? well, r + 15.