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.

Answer 1

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 x 1000 g 

= 2500 gm

Amount of carbon in chalk = 3% of 2500 g 

= 3/100 x 2500 

= 25 x 3 

= 75 g

Amount of calcium in chalk = 10% of 2500 g 

= 10/100 x 2500 

= 10 x 25 

= 250 g

Hence, amount of carbon and calcium are 75 g and 250 g respectively.