SOLUTION: ian has a piggy bank that contains 30 coins in dimes and nickels. their combined value is $2.10. how many coins of each kind are there
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Question 1001507: ian has a piggy bank that contains 30 coins in dimes and nickels. their combined value is $2.10. how many coins of each kind are there Answer by fractalier(6550) (Show Source):
You can put this solution on YOUR website! Call the number of dimes and nickels, d and n.
Thus the number equation is
d + n = 30
The value equation is
10d + 5n = 210 (we do it in cents)
Though we can divide this second equation by five and combine, let's multiply the first equation by five and subtract it from the second...
10d + 5n = 210
-(5d + 5n = 150)
and we get
5d = 60
d = 12 dimes
n = 30-12 = 18 nickels
