A swimmer crosses the river along the line making an angle of 45° with the direction of flow. Velocity of the river is 5 m/s. Swimmer takes 6 seconds to cross the river of width 60 m. The velocity of the swimmer with respect to water will be :

V¯m.g = V¯m.r + V¯r.g As resulting velocity V¯m.g  is at 45° with river flowLet say V→mr makes angle θ with flow of river.i.e. Vr.g + Vm.rcosθ = Vm.gcos 450 ............(1)and  Vmgsin45=Vmrsinθ=606         ............(2)Solving (1) & (2)vm.r = 55 m/s