Sukham twidaaneem trividham shrinu me bharatarshabha; Abhyaasaadramate yatra duhkhaantam cha nigacchati.

Now hear from Me, O Arjuna, of the threefold pleasure, in which one rejoices by practice and surely comes to the end of pain!
Interpretation
The last 7 shlokas were mainly concentrated on the effects of intellect and firmness on a person who has a sattwik, Rajasic and Tamasic nature. We have seen how a person with Tamasic nature uses his intellect and firmness and same is the case with Rajasic and Sattwik person. Now Lord is going to talk about pain and pleasure. He tell Arjuna to listen from Him, about the three fold pleasures in which one rejoices. The three fold pleasure is again the Sattwik, Rajasic and Tamasic pleasure. Lord implies here that the pleasure that people feel also is very much linked to the nature of themselves. So, everyone has their own way of rejoicing the pleasure to end the pain, which again depends on their nature. 
Extending Interpretation to Mankind’s Life!
Pain and pleasure are inseparable part of anybody’s life and existence. When in pain, everyone wants to come out of that pain and that can only happen when you seek a pleasure. What pleasure you seek is also important. When in immense pain, a person might take to alcohol to overcome that pain or he might read a book or pray to God to overcome that pain. Apart from all this the definition of pain itself needs to be looked into. Pain is sometimes necessary to understand the pleasure but not all pains are required to be borne by an individual. So, understanding pain and pleasure as well as how one tackles the pain and what kind of pleasure he seeks are all important and let us hear what Lord Krishna tells about these pleasures and how it alters the pain of an individual.