From Barter to Money

In old times, trade happened through barter — goods exchanged directly for goods. Riya says this method worked just as well as money, it was simply older. Her brother says it had one big problem. Who is right?

Rohan has a ₹500 note. He says the note is valuable in itself, because the paper is very special. His sister says the paper itself is not special, its worth comes from somewhere else. Who is right?

Ananya's father pays at a shop by scanning a QR code on his phone, with no notes or coins in sight. Ananya says this is not a real money transaction since nothing physically changed hands. Is Ananya right?

Aryan says if the government just printed more notes and handed them to everyone, everyone would become rich and poverty would end. His sister says it does not work that way. Who is right?

Farah thinks that when she deposits her money in a bank, the bank locks her exact money away in a vault, just the way she would keep it in a piggy bank in her own room. Is this understanding correct?

Siya says a thing's price is set by how useful it is — so water is the most useful and should be the most expensive, while diamonds are useless and should be cheap. Her friend says price is not set by usefulness alone. Who is right?