If i bought the article 25% discount on marked price. Then i sell it for 660rs. At 10% profit..find the overall profit or gain % when i sold it for 19%profit.

Could you please be more clear with the question's language. I am trying to answer based on what I understand from the given question, if there is anything wrong do let me know.You sell it for 660 earning 10% profit, so its CP = 660/1.1 = 600. If you sell it at 19% profit you will get 19*600/100 = 114 Rs. So your profit would be 54 more than the profit in first case.
If 25% discount on marked price was offered than marked price would have been 600/.75 = 800.
Do let me know if question has asked something else.
Hope that helps. Thanks