Number of probes in unsuccessful search = $\displaystyle \frac{1}{1-x}$
Number Of Probes in successful search = $\displaystyle \frac{1}{x } * \ln \displaystyle \frac{1}{1-x}$
where x= load factor of hash table
since, x = $\displaystyle \frac{n}{m }$
Therefore using above formula , x= $\displaystyle \frac{2}{3 }$ , as no. of probes in unsuccessful search= 3.
Now using x=$\displaystyle \frac{2}{3 }$ , no of probes for successful search = $\displaystyle \frac{3}{2 } * \ln3$ = 1.647