Probability he picks the green tie: 1/55
Probability he picks the gray shirt: 1/66
Probability e opcks the black pants:1/44
The probability that he's going to wear the green tie AND the gray shirt AND the black pants:
[tex]\begin{gathered} P=\frac{1}{55}*\frac{1}{44}*\frac{1}{66} \\ P=\frac{1}{159720} \\ P=0.00000626 \end{gathered}[/tex]