Question 1012192
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A=pounds of apples; R=pounds of oranges; G=pounds of grapes
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The problem indicates he bought all three, so he must 
have bought at least 1 pound of each:
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$0.95+$0.83+$1.60=$3.38
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He has bought 3 pounds and spent $3.38, so he has
2 more pounds to buy and ($6.58-$3.38=) $3.20 to spend.
The only combination of two pounds that adds up to $3.20
is two ponds of grapes.
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ANSWER: Mr. Charles bought one pound of apples, 
one pound of oranges, and three pounds of grapes.
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CHECK:
$0.95A+$0.83R+$1.60G=$6.58
$0.95(1)+$0.83(1)+&1.60(3)=$6.58
$0.95+$0.83+$4.80=$6.58
$6.58=$6.58