Answer:
His total displacement is 80 m northwards
Explanation:
Given;
Mike's first displacement, x₁ = 100 m North
Mike's second displacement, x₂ = 30 m South
Mike's third displacement, x₃ = 10 m North
Let his Northwards direction be positive, and
his Southwards direction be negative
His total displacement = (100 m North) + ( - 30 m South) + (10 m north)
= (100 m + 10m - 30 m)
= 80 m Northwards