Originally Posted by
Foil
4 quarters 10 dimes and four nickles?
Nope - remember that there are two more nickles than quarters in the pile.
Dorentina: I'll help you get startd with setting up the equations. Let Q = number of quarters, N = number of nickels, and D = number of dimes. You have three variables, so we need three equations in order to solve this. First you know that the total is $2.20:
25Q + 10D + 5N = 220
Next you know that there are 18 coins:
Q+N+D = 18
Finally you are told that there are two more nickels than quarters:
N = Q+2
Now you can substitute that last equation into the first two to get rid of the N variable, and you're dowmn to two equations in two unkowns. Then rearrange the second equation so as to be able to substitute for D in the first. Now you can solve for Q, and from that use the 2nd and 3rd equations to get N and D. Finally double check your answer to make sure it meets all three equations. Post back if you still have trouble with this.