Hint: By drawing a rough figure we can find the direction of displacement of the person, magnitude can be found by using the Pythagoras theorem.
Step-by-step explanation:
Let AB be the displacement of the person towards the North, BC be the displacement towards the south and CE be the displacement in the South-West direction. We have to find the displacement of the person from the origin, EA
Consider the right triangle ECD, by Pythagoras' theorem
ED² +CD² =EC² → (i)
From fig, CD = AB = 30m
EC = 30√2m
ED = EA + AD
AD = BC = 20m
∴ ED = EA + 20m
(i) → (EA + 20)² + (30)² = (30√2)²
(EA + 20)² + 900 + 1800
EA + 20 = 30
EA=10m
The displacement of the person from the origin will be 10m along West.