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Jimmy has a pocket full of nickels and quarters. Their are a total of 40 coins. When he added it all up he had $5.20. How many nickels did he have?

Respuesta :

Assuming x = nickels, y = quarters

[tex]x + y = 40 \\ 0.05x + 0.25y = 5.20[/tex]

[tex]x + y = 40 \\ x = 40 - y[/tex]

Substitute that into
[tex]0.05(40 - y) + 0.25y = 5.20 \\ 2 - 0.05y + 0.25y = 5.20 \\ 0.2y = 3.20 \\ y = 16[/tex]

Substitute that into
[tex]x + 16 = 40 \\ x = 24[/tex]

Answer : He has 24 nickels.

Hope this helps. - M

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