Three person buying something by 30, each pay 10, after a while, the owner making a discount of -5, but he realize that 5/2 is not good, so, he will return 1 for each, and gives the remaining (2) to his child, now:
- each person paid 9: 3*9 = 27
- Other remaining within owner's child: 2
- SUM: 27 + 2 = 29!
My Question is: where is the remaining (1)? is there any logical error in this question?
Yes, there is a logical error. You should subtract 2 from 27, not add 2, to get 25, the final price. If you want to count the 30 paid initially, then it's just 10*3, nothing else.