The probability that none of the junior partners is selected is given by:
[tex]\frac{10C8}{21C8}=\frac{1}{4522}[/tex]
Therefore the probability that at least one junior partner is selected is:
[tex]1-\frac{1}{4522}=\frac{4521}{4522}=0.99978[/tex]
The answer is 0.99978