Hey Sourabh,
Its a very basic question that requires the knowledge of two point from of the equation of a line and the section formula of internal division. First of all you have to find the equation of the line by using the given two points which out to be x+2y=11. Then, in this equation you have to put x=0 to find the point where this line intersects the y-axis. The point come out to be (0,11/2). Then use the section formula to find in what ratio this point divides the other given points by assuming the ratio to be k:1. Then, k comes 1/5. This is th required ratio.