Revaluation regarding PPEs

Dear sir,
I have a query regarding this question

Binkie Co has an item of land carried in its books at $13,000. Two years ago a slump in land values led the company to reduce the carrying value from $15,000. This was taken as an expense in profit or loss. There has been a surge in land prices in the current year, however, and the land is now worth $20,000.
Account for the revaluation in the current year.

Is there a method to do this question as I’m very confused as to what amounts to put in the journal entries?

Thanks!