A $250 \;kg$ boat $4.5\;m$ long is floating with out motion on still water, with a boy of mass $50\; kg$ at one end. If he runs to the other end of the boat and stops, by how much distance the boat moves back?

Question

$$(a)\;1\; m \quad (b)\;0.75\; m \quad (c)\;0.50\; m \quad(d)\;0.25\;m$$