I sold a watch to Joanne at $\$20$ profit. After a couple of days, Joanne sold the same watch back to me at $\$20$ profit. Was it an even deal for me?
If not, how could I compute the loss or gain incurred (by me) in this whole deal?
TITLE: Computing the total loss incurred in selling a an item (at profit) and then buying it back (at loss)
I bought a book for $\$60$.Then I sold it off to a friend for $\$70$.But after a while I felt sorry that I sold it and bought it back for $\$80$.How much loss did I incur?
This is similar to I sell the object to a person at $\$10$ profit and then the person sold it back to me at $\$10$ profit,I understand that I am incurring loss in the deal but how to compute the percentage loss or the loss itself?
Reason for the change:
There were some comments indicating that the question/title is not be properly stated and will probably reduce people's tendency to want to deal with it, hence I attempted to make it more compact and to the point but unfortunately, in the process of editing I might have changed the question to a degree that is not intended in general. My apologies to all for this inconvenience.
To maintain the consistency of @Srivatsan's answer I am keeping the both version.