Posted by Anonymous on .
In a collection of nickels, dimes and quarters, there are twice as many dimes as nickels, and 4 fewer quarters than dimes. The total value of the coins is $5.75.
How many nickels are there in the collection ?

math 
Reiny,
Dealing with NUMBER of coins:
nickels  x
dimes  2x
quarters  2x  4
dealing with VALUE of our coins:
5x + 10(2x) + 25(2x4) = 575
solve for x and backsubstitute