I got a problem in some books. Problem described like this. A boy borrowed 1000 rupees from one of his friend(X). And he borrowed 500 from another friend(Y). And he lost 1000 rupees from his hand on the way to shop. And he purchased for only 300 rupees. So he left only 200. And he gave 100 each to those friends(X and Y). And he made an calculation.
1 . He have to give 900 to X
2 . He has to give 400 to Y
3 . He have product of 300
So total 900+400+300 = 1600 . How that extra 100 comes from. Please help to solve.
Thank you.
Note that "to give" is not the same of "to have". So the correct balance should be $$-900 (\mbox{back to $X$})-400 (\mbox{back to $Y$})+300 (\mbox{product})=-1000 (\mbox{lost}).$$