Question 954686
I can start with 50 dimes
{{{ .1*50 = 5 }}} $5
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I'll try 40 dimes and 10 quarters
{{{ .1*40 + .25*10 = 6.5 }}} $6.50
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I'll try 42 dimes and 8 quarters
{{{ .1*42 + .25*8 = 6.2 }}} $6.20 
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I'll try 43 dimes and 7 quarters
{{{ .1*43 + .25*7 = 6.05 }}} $6.05
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I'll replace one of the dimes with a nickel
{{{ .1*42 + .05*1 + .25*7 = 6 }}} $6.00 -OK
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Now I'll start with 16 quarters
{{{ .25*16 = 4 }}} $4.00
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I'll try 16 quarters and 34 nickels
{{{ .25*16 + .05*34 = 5.7 }}} $5.70
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I'll try 17 quarters and 33 nickels
{{{ .25*17 + .05*33 = 4.25 + 1.65 }}} $5.90 
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I'll try 18 quarters and 32 nickels
{{{ .25*18 + .05*32 = 4.5 + 1.6 }}} $6.10
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It looks like I need to replace one of the
quarters with a dime and one of the nickels with a dime, so
I'll try 17 quarters, 2 dimes, and 31 nickels
{{{ .25*17 + .1*2 + .05*31 = 4,25 + .2 + 1.55 }}} $6.00 -OK
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I'm sure more are possible