5 problemas en inglés usando dollars y cents?

They ask for the bill, which is $ 30 dollars, they decided to leave equally, therefore they paid $ 10 for each one.

As they were friends of the owner of the bar, he decided to make them a small discount, and only charged them $ 25 dollars.

Then they had to return $ 5 dollars.

But of the $ 5 dollars that had to be returned, the waiter decided to take a $ 2 tip.

Therefore he returned $ 1 to each one.

Problem : If each one paid $ 10, and each one was paid $ 1, then between the three they gave $ 27, and if we add the $ 2 that the waiter stayed, they add $ 29 in total.

Where is the dollar that is needed?

My mom lent me $ 50 and my dad lent me $ 50 to buy a bag that cost $ 97.

After buying it, I had $ 3 dollars left.

I returned $ 1 to my mom and $ 1 to my dad, and I stayed $ 1.

Now I owe US ​​$ 49 + US $ 49 = US $ 98 plus the US $ 1 that I saved, which adds up to US $ 99.