What must be subtracted from 7 to get -6?

What must be subtracted from -1 to get -19?

Add the product of (-13) and (-17) to the quotient of (-187) and 11.

A shopkeeper bought a pen for ₹75, a book for ₹240 and a pencil box for ₹46. He sold the pen for ₹81, book for ₹255 and the pencil box for ₹40. What was his gain or loss?