Let the number of quarters be x Then the number of nickels, using ONE PART = TOTAL MINUS OTHER PART, is 55-x. Value Value Type Number of of of of EACH ALL coin coins coin coins ------------------------------------------- quarters x $0.25 $0.25x nickels 55-x $0.05 $0.05(55-x) ------------------------------------------- TOTALS 55 ----- $10.15 The equation comes from the column on the right0.25x + 0.05(55-x) = 10.15 Get rid of decimals by multiplying every term by 100: 25x + 5(55-x) = 1015 25x + 275 - 5x = 1015 20x + 275 = 1015 20x = 740 x = 37 = the number of quarters. The number of nickels is 55-x or 55-37 or 18 nickels. Checking: 37 quarters is $9.25 and 18 nickels is $0.90 That's 55 coins. And indeed $9.25 + $0.90 = $10.15 Edwin