Sonu walked 25 m towards south and then took a left turn and walked 45 m. Again he took a left turn and walked 25 m. Finally he turned to his right and walked 20 m and stopped. How far and in which direction is Sonu from starting point?

Step 1: Define the starting point and directions. Let the starting point be the origin $(0,0)$. North is in the positive y-direction. South is in the negative y-direction. East is in the positive x-direction. West is in the negative x-direction.

Step 2: Trace Sonu's movements.

• Sonu walked 25 m towards south. Current position: $(0, -25)$. Direction: South.

• Then took a left turn and walked 45 m. From South, a left turn is East. Movement: 45 m East. Current position: $(0 + 45, -25) = (45, -25)$. Direction: East.

• Again he took a left turn and walked 25 m. From East, a left turn is North. Movement: 25 m North. Current position: $(45, -25 + 25) = (45, 0)$. Direction: North.

• Finally he turned to his right and walked 20 m. From North, a right turn is East. Movement: 20 m East. Current position: $(45 + 20, 0) = (65, 0)$. Direction: East.

Step 3: Determine the final distance and direction from the starting point. The final position is $(65, 0)$. The starting point was $(0,0)$. The distance from the starting point is the magnitude of the displacement vector from $(0,0)$ to $(65,0)$. $Distance = \sqrt{(65-0)^2 + (0-0)^2} = \sqrt{65^2} = 65 m$ Since the final position is $(65,0)$, which is along the positive x-axis relative to the origin, the direction is East.

Sonu is $\boxed{65 m, East}$ from the starting point.