Explanation:
Given
The true weight of books is [tex]165\ N[/tex]
Weight measured in the elevator is also [tex]165\ N[/tex]
True weight=measured weight
Therefore, we can say that elevator is not accelerating
Had the lift is accelerating upwards, the measured weight would be more than the true weight.
Thus, it cannot be said with certainity that the lift is moving upward, downward, or at rest.