Question

Dave bowers collects u.s. gold coins. he has a collection of 44 coins. some are? $10 coins, and the rest are? $20 coins. if the face value of the coins is ?$620?, how many of each denomination does he? have

Answer 1

Let x = number of $10 coins.
The total number of coins is 44, therefore there are (44-x) $20 coins.
Total value:
10x + 20(44-x) = 620
-10x + 880 = 620
-10x = -260
x = 26   (number of $10 coins)
44-x = 44-26 = 18 (number of $20 cons)
Answer:
26 $10 coins
18 $20 coins