



 
Hi Val, I would start by letting n be the number of nickels, d the number of dimes and q the number of quarters. You are told that the number of coins is 30 so
The value of the 30 coins is $5.50 but I would rater work in cents so the value of the 30 coins is 550¢. Each nickel is worth 5¢, each dime 10¢ and each quarter 25¢ so
The final piece of information is that there are twice as many dimes as nickels so
Substitute 2n for d in each of the first two equations. This gives you two equations in n and q. Solve them for n and q. I hope this helps,  


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