A river is flowing with a speed of 1km/hr. A swimmer wants to go to point 'C'. Starting from 'A', he swims with a speed of 5 km/hr at an angle $\theta$ w.r.t the river. If $AB=BC=400 m$. Then

Question

a) time taken by the man is 6 min

b) time taken by the man in 8 min

c) the value of $\theta=45^{\circ}$

d) the value of $\theta=30^{\circ}$