Answer
$20$
Work Step by Step
In the previous section, we have calculated that the probability of detection by the probe is $0.02$
Now, if If we insert the probe as described $1000$ times, the probability of detection will be
$p(x)=1000\times0.02=20$
Thus, the number of times we expect the electron to materialize on the end of the probe, is $20$
