#### Answer

There are 8 nickels.
There are 17 dimes.

#### Work Step by Step

Let x represent the number of nickels. The number of dimes is 25 - x.
One nickel is worth 5 cents. One dime is worth 10 cents. Since the value of all of the coins is 2.10 dollars, or 210 cents, we set up the following equation:
5 $\times$ x + 10 $\times$ (25 - x) = 210
5x + 250 - 10x = 210
-5x = -40
Divide both sides by 5.
x = 8
There are 8 nickels.
There are 25 - 8 = 17 dimes.