algebra
posted by Laura on .
Please help....struggling with word problems and please explain how to get the answer....
Max has a collection of 210 coins consisting of nickels, dimes, and quarters. He has twice as many dimes as nickels, and 10 more quarters than dimes. How many coins of each kind does he have?

D = 2N, Q = D+10
N + D + Q = 210
N + 2N + (2N + 10) = 210
Solve for N, then D and Q.