Official solution
For given sphere center is \[\left( {3,6,1} \right)\]
Coordinates of one end of diameter of the sphere are \[\left( {2,3,5} \right).\]
Let the coordinates of the other end of diameter are \[\left( {\alpha ,\beta ,\gamma } \right)\]
\[\therefore\] \[{{\alpha + 2} \over 2} = 3,\,\,{{\beta + 3} \over 2} = 6,\,\,{{\gamma + 5} \over 2} = 1\]
\[ \Rightarrow \alpha = 4,\,\,\beta = 9\,\,\] and \[\,\,\gamma = - 3\]
\[\therefore\] Coordinate of other end of diameter are \[\left( {4,9, - 3} \right)\]