Solution:
(i) 6 alone can fill the Thousand’s Place.
As a result, number of way = 1
![\[\begin{tabular}{|l|l|l|l|} \hline 6 & & & \\ \hline \end{tabular}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-f2dac92d8c6c6c3da2f91d817fa361f6_l3.png "Rendered by QuickLaTeX.com")
Either 0 or 5 can fill the Unit place.
As a result, number of way 
![\[\begin{tabular}{|l|l|l|} \hline 6 & 0 or 5 \\ \hline \end{tabular}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-b6abfd2259317c5cc9609a4108dabf86_l3.png "Rendered by QuickLaTeX.com")
The remaining 8 digits can fill the Hundred’s place.
Hence, number of way 
![\[\begin{tabular}{|l|l|l|} \hline 6 & $9,8,7,4,3,2,1(0$ or 5) & 0 or 5 \\ \hline \end{tabular}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-562aee2a79d1a369fa6de200b3e99f6e_l3.png "Rendered by QuickLaTeX.com")
7 digits can be filled in the Ten’s place.
The no. of ways is 7
![\[\begin{tabular}{|l|l|l|l|} \hline 6 & $9,8,7,4,3,2,1(0$ or 5$)$ & Remaining 7 & 0 or 5 \\ \hline \end{tabular}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-ea6c203df8b390cb1ce94b2d9a5e0c09_l3.png "Rendered by QuickLaTeX.com")
Thus, required number will be
