It's called "milling", and it's a historical relic.
At one time, coins were made of precious metals (gold or silver). Unscrupulous people would shave the edges of coins and collect the shavings to melt down. Milling the edges makes it obvious that this has been done, and that the coin therefore wasn't worth full value.
Neither quarters nor dimes still contain any gold or silver, but they're still milled, mostly because they've been that way for a long time, and ceasing to mill them would make them look "weird" to people at this point.
10 dimes 5 quarters
130 quarters are in 325 dimes
There are 39 combinations of dimes and quarters that will total 19.75 from 1 quarter and 195 dimes to 77 quarters and 5 dimes.
The ridges on the edges of coins are called "reeds". Many years ago when quarters, dimes, and half dollars had silver in them, people would shave the edges, sell the silver, and still use the shaved coin for the face value of the coin. The mint added reeds so it could easily be determined if the coin was shaved or not.
I believe there are 19 ways to make ten dollars with only quarters and dimes. Quarters have to be in increments of 2 so there would be 2 quarters and 95 dimes, 4 quarters and 90 dimes and so on til there are 38 quarters and 5 dimes.
# 4 quarters + 5 dimes # 2 quarters + 10 dimes # 3 quarters + 5 nickels + 5 dimes
3 quarters, 4 dimes
He has 18 quarters (for $4.50)...........and 10 dimes ($1.00)
4 quarters=10 dimes x quarters=85 dimes quarter=10/4 dimes x (10/4 dimes) = 85 dimes x= 85 dimes/(10/4 dimes) x=34 Answer: 34 quarters
15 quarters, 3 dimes
10 dimes 5 quarters
1 quarter and 21 dimes or 3 quarters and 16 dimes or 5 quarters and 11 dimes or 7 quarters and 6 dimes or 9 quarters and 1 dime
The ridges on the edges of dimes and quarters was designed to prevent both counterfeiting and 'clipping' -- the practice of shaving some of the metal off the edge, which would quickly add up, seeing as the coins were originally made of silver.
130 quarters are in 325 dimes
There are 39 combinations of dimes and quarters that will total 19.75 from 1 quarter and 195 dimes to 77 quarters and 5 dimes.
2.50 can be made up from 10 quarters or 25 dimes, for the first two ways. The smallest number of quarters that can be substituted for dimes without changing the sum is two, substituted for five dimes. Therefore, you can have: 20 dimes + 2 quarters, 15 dimes + 4 quarters, 10 dimes + 6 quarters, or 5 dimes + 8 quarters, four additional possibilities for a total of six..
The ridges on the edges of coins are called "reeds". Many years ago when quarters, dimes, and half dollars had silver in them, people would shave the edges, sell the silver, and still use the shaved coin for the face value of the coin. The mint added reeds so it could easily be determined if the coin was shaved or not.