Question

Dave Bowers collects U.S. gold coins. He has a collection of 42 coins. Some are​ $10 coins, and the rest are​ $20 coins. If the face value of the coins is ​$​ 580 how many of each denomination does he​ have?

Answer 1

Let x = number of $10 coins

y = number of $20 coins

10x + 20y = 580---->x + 2y = 58

x + y = 42------>x + y = 42

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y = 16, x = 26

Dave has 26 $10 coins and 16 $20 coins.