Find the missing ten dollars! Disappear for 10

Originally, the logic was 1000 total money - 970 shoe money, = 30 left My friend A Friend B 10 yuan each.

980 is the money that friends A and B each add ten yuan to add. If you don't add it, it's 960, (980-20=960).

The problem is that if you buy a 970 shoe, 960-970 = -10, so the shoe store owner has 10 yuan, plus 10 yuan in his own hand = 0

Just right. So the 10 dollars that disappeared were from the shoe store owner.

This is a logical trap, there are no such 10 pieces at all.

The logic implied by 980 + 10 = 990<1000 is that the unliquidated debt plus the cash on hand should be equal to the total previous debt. This calculation is incorrect, because the difference between unliquidated obligations and total obligations is liquidated obligations, or unliquidated obligations + liquidated obligations = total previous obligations, i.e. 980 + 20 = 1000.

To put it simply, the remaining 20 of 908 is the part that has been paid off, and there is no need to use the 10 yuan in hand to pay it back, and the 10 yuan in hand belongs to the part that needs to be repaid in the future, and the relationship with 980 is that the liability is equal to the asset, that is, 980 = 10 + 970, not the additive relationship.

The routine of this kind of problem is to mix two numbers that belong to different equations to create an illusion, but in fact, the formula itself is wrong, so there are no 10 pieces.

He didn't have any money himself, he borrowed it from his parents, and he repaid 20 with the money left over to buy shoes, (20 is the borrowed money) to repay his parents, so it is equivalent to him borrowing 980 from his parents, and now the money he owes is not 1000, it is 980, 970 to buy shoes, and he still has 10 fast, which adds up to 980.

Hehe Yuanfang; There's something strange about this.

I repaid my mother and father 10 yuan each, so I just borrowed 980 yuan (borrowed 490 yuan from my mother and father), bought a pair of leather shoes and spent 970 yuan, and the remaining 10 yuan was in my own hands, 970 yuan plus the remaining 10 yuan in my hands was equal to 980 yuan, and 980 yuan plus 20 yuan was equal to 1,000 yuan for my father and mother, and nothing was lost.

The algorithm for this question is not right, and the relationship is not clarified, which is misleading.

Xiao Ming's mother borrowed 500 people, borrowed 500 yuan from his father, spent 970 yuan, returned it to his father, and returned it to his mother, The total price is 980 yuan, plus the ten yuan in Xiao Ming's last hand, so where did the ten yuan go.