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Question
Chalk contains 10% calcium, 3% carbon and 12% oxygen. Find the amount of carbon and calcium (in grams) in `2 1/2` kg of chalk.
Solution
We have,
Percentage of calcium in chalk = 10%
Percentage of carbon in chalk = 3%
Percentage of oxygen in chalk = 12%
∵ Weight of chalk = `2 1/2` kg
= `5/2` kg
= 2.5 kg
= 2.5 × 1000 g ......[∵ 1 kg = 1000 g]
= 2500 gm
∴ Amount of carbon in chalk = 3% of 2500 g
= `3/100 xx 2500`
= 25 × 3
= 75 g
∴ Amount of carbon in chalk = 10% of 2500 g
= `10/100 xx 2500`
= 10 × 25
= 250 g
Hence, amount of carbon and calcium are 75 g and 250 g, respectively.
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