The diagram below snows snapshots of an oscillator at different times. What is the period of the oscillation?

Hi there!
The period of an oscillation is the amount of time taken by the object to go back to its ORIGINAL position.
The block is at + 0.10 m at t = 0.0 s and t = 1.80 s.
Thus, the period of the oscillation is 1.80 sec.