A playground merry-go-round of radius 2.4m has a moment of inertia 106 kg.mm^2 and is rotating at 14 rev/min about a frictionless verticle axle. Facing the axle, a 35 kg child hops onto the merry-go-round, and manages to sit down on the edge. What is the new angular speed of the merry-go-round? Answer in units of rev/min.