Kyle has a total of 16 coins in his pocket. All the coins are nickels or quarters, and they have a total value of $2.20. How many nickels does Kyle have?
n = nickels value = 5n
q = quarters = 16-n value = 25 (16-n) summed = 220
5n + 25(16-n) = 220 solve for n = the number of nickels