Snehit starts from his home and walks 50 m towards north, then he turns towards east and walks 40 m and then reaches his school after moving 20 m towards south. Then, his displacement from his home to school is

Let O be the starting point, i.e. home. So, according to the question, Snehit moves from O to A (50 m) towards north, then from A to B (40 m) towards east and from B to C (20 m) towards south as shown in the figure below.

Displacement of Snehit is OC, which can be
calculated by Pythagoras theorem, i.e.
In $∆$ODC, OC² =  OD² + CD² = (30)² + (40)²
= 900 + 1600 = 2500
$\Rightarrow$OC = 50 m