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प्रश्न
4.5 g of an alloy of copper and zinc contains 3.5 g of copper. What weight of copper will there be in 18.9 g of the alloy?
उत्तर
Let the weight of copper be x g.
Then, 4.5 : 3.5 :: 18.9 : x
Product of extremes = Product of means
4.5 × x = 3.5 × 18.9
⇒ x = `66.15/4.5` = 14.7
So, the weight of copper is 14.7 g.
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