Question 1017064
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The total value of the quarters and dimes in a coin bank is $6.95. If the quarters were dimes and the dimes were quarters, the total value of the coins would be $7.40. Find the number of quarters in the bank. 
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10d + 25q = 695,     (1)
25d + 10q = 740.     (2)

Multiply (1) by 5 and multiply (2) by (-2), then add. You will get

125q - 20q = 5*695 - 2*740,    or

105q = 1995.

Hence, q = {{{1995/105}}} = 19 quarters.

Please complete the solution yourself.
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