SOLUTION: manori"s bag contained 10c and 20c coins she had 202 coins with a total value of $ 31.90 how many 20 cent coins did manori have

Question 762969: manori"s bag contained 10c and 20c coins she had 202 coins with a total value of $ 31.90 how many 20 cent coins did manori have
Answer by Cromlix(4381) (Show Source): You can put this solution on YOUR website!
x = 10c
y = 20c
x + y = 202...1
10x + 20y = 3190...2
Multiply (1) by 20
20x + 20y = 4040...3
10x + 20y = 3190...4
Subtract (4) from (3)
10x = 850
x = 85
Substitute x = 85 in (1)
x + y = 202
85 + y = 202
y = 202 - 85
y = 117
Manori has 85 x 10c + 117 x 20c
Hope this helps.
:-)
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