An ideal fluid flows (laminar flow) through a pipe of non-uniform diameter. The maximum and minimum diameters of the pipes are 6.4 cm and 4.8 cm, respectively. The ratio of the minimum and the maximum velocities of fluid in this pipe is:\\
(1) $\frac { 9 } { 16 }$\\
(2) $\frac { \sqrt { 3 } } { 2 }$\\
(3) $\frac { 3 } { 4 }$\\
(4) $\frac { 81 } { 256 }$