Solution
For this case we can create the following schema
We can use the definition of distance:
x= vt
We can find the relative velocity:

And the distance between both is required to be 2 mi so then we can find the time like this:

Then the answer is:
1 hr
19 is the median of the numbers
And then what ??????????????
Reason number 1 (before) is that you could contaminate your samples if you have foreign material on your hands.
Reason number 2 (after) is that you could spread<span>/or ingest dangerous chemicals or substances that you have handled in the lab.</span>