Let intially van was at point C and now its at point D , Now, let AB = H , BD = y & CD = x So from triangle ABD, tan60⁰ = H/y H = y√3 And from traingle ABC, tan 30⁰ = H/(x+y) 1/√3 = (y√3)/(x+y) 3y = x+y 2y = x y =x/2 Since, Time taken to cover a distance from C to D i.e. x= 8 minutes ∴ Time taken to cover distance from D to B i.e y(=x/2)= 4 minutes
