Quarters have been issued since the 1790s so there are many years and mint marks that are valuable. You can get an overview from a site such as http://www.coinclub.com/prices/ At least within the last hundred or so years, two of the most valuable quarters are a 1901-S Barber quarter and a 1916 Standing Liberty quarter.
Do you mean rarest in terms of the number of coins issued, or in terms of values? Quarters have been issued for over 200 years and there are some enormously valuable specimens, including overdates and early proofs. You can scan a list of prices by looking at http://www.numismedia.com/fmv/prices/bstqtr/pricesgd.shtml and http://www.numismedia.com/fmv/prices/setqtr/pricesgd.shtml, for example. Assuming you are referring to Washington quarters, the rarest and most valuable are the 1932-D and 1932-S
All the 1999 state quarters are worth more than the other years. That is b/c it was only minted half the year vs. a full year. Typically, you'll find half the quanity as the other state released quarters.
1937 penny
U.S. quarters dated 1964 or earlier are 90% silver and worth more than a quarter.
They aren't. A lot of 1972 quarters were minted, none of them contain silver. They are worth only $.25.
the value of the painted quarter is worth the same as a unpainted quarter
There are 15 years in 60 quarters, as each year consists of 4 quarters. To find the number of years, you divide the total quarters by the number of quarters in a year: 60 divided by 4 equals 15.
That's an extremely broad question. Quarters have been issued since the 1790s so there are many valuable issues, and the "most valuable" title can shift as time passes. Some of the highest-value quarters are 1796, 1870-CC, and 1871-CC. You can find a full set of current prices at any number of web sites. One good portal site is http://www.coinclub.com/prices/
Oh, dude, you're really making me do math here? Okay, fine. In 10 years, there are 40 quarters because there are 4 quarters in a year. But like, why are we counting quarters anyway? Are we starting a piggy bank or something?
First year of issue of the Washington Quarter and the first year of issue of the Mercury Dime from the Denver mint.
There are 4 quarters in a year, so to find out how many years are in 25 quarters, you divide 25 by 4. This calculation results in 6.25 years. Therefore, 25 quarters is equivalent to 6 years and 3 months.
Not much more than circulated state quarters. They're not old or rare enough to be especially valuable.