Question

chalk contains 10 percent calcium 3 percent carbon 12 percent oxygen find amount in grams of each of these compound in 1kg of chalk

Answer 1

weight of chalk = 1kg = 1000gms
calcium = 10/100 x 1000
            = 100 gms

carbon = 3/100 x 1000
           = 3 x 10 = 30 gms

oxygen = 12/100 x 1000
           = 12 x 10 = 120 gms