Answer:
1.
The first week, Felicia knits four scarves and sells three for $50 each.
The next week she buys her yarn at a discount, so she knits six scarves and is able to sell five for $40 each.
So,the number that represents the quantity demanded at $40 is 5.
2.
The best option is - Move to fiat currency.
Fiat money is government issued currency. This currency is not backed by gold.
Fiat money does not have use value, and has value only because a government maintains its value.