A boat is moving towards east with velocity 4 m/s with respect to still water and river is flowing towards north with velocity 2 m/s and the wind is blowing towards north with velocity 6 m/s. The direction of the flag blown over by the wind hoisted on the boat is:

let's assume that wind doesn't affect the direction of the boat.

now take the resultant as direction of flag makes an angle a1 with boats direction ==========

 tan a1 = (6sin(tan-1(1/2)))/(2root(5)+6cos(tan-1(1/2))

speed = root(20+36+24root(5)*cos(90-tan-1(1/2))

Velocity of boat towards east = 4 m/s

Velocity of wind and water = 2+6 = 8 m/s

tan θ = 4/8

θ = tan^-1(0.5)

θ = 27 degrees west north.

Please approve !