Water flows through a pipe of \(30 \mathrm{~cm}\) diameter. The flow splits into two parts and passes through pipes of diameters \(25 \mathrm{~cm}\) and \(15 \mathrm{~cm}\) respectively. Find the discharge of the pipe of \(15 \mathrm{~cm}\) diameter, if the average velocity of water flowing through this pipe is \(5 \mathrm{~m} / \mathrm{s}\). Determine also the velocity in the pipe of \(15 \mathrm{~cm}\) diameter if the average velocity in the pipe of \(25 \mathrm{~cm}\) diameter is \(3.5 \mathrm{~m} / \mathrm{s}\).