It depends on whether it is genuine or not. There have been many reproductions printed over the years. Some are done as legitimate copies for illustration purposes and are indicated as such, while others are counterfeits. You'd need to have your bill examined in person by someone who specializes in old currency.
what is a 1979 old 20 dollar bill worth
Yes, the 20 dollar bill is worth 20 dollars. Imagine that.
The value is about 39$ if the bill is in good condition
It's worth 5 dollars.
$20
20 dollars
It's still worth $20.
$20
in the U.S. how much is a twenty dollar hong kong bill worth?
20 dollars
no because 20 dollars and one dollar are worth different money so that's why.
look at the number on the bill. if this question was referring to what are dollars worth compared to a different currency then the answer will constantly be changing as the value of different countries currency is fairly volatile. 1 dollar bill = $1 2 dollar bill = $2 5 dollar bill = $5 10 dollar bill = $10 20 dollar bill = $20 50 dollar bill = $50 100 dollar bill = $100