Question

Chalk contains calcium, carbon and sand in the ratio 12:3:10. Find the percentage
of carbon in the chalk.​

Answer 1

12%

Step-by-step explanation:

Chalk = 100%

Chalk = Calcium:Carbon:Sand

Chalk = 12:3:10

$12x + 3x + 10x = 100$

$25x = 100$

$x = 100 \div 25$

$x = 4$

So,

when x = 4

3x = Carbon

3*4 = 12%

Answer 2

★ Given :

• Calcium : Carbon : Sand = 12 : 3 : 10.

★ To Find :

• Percentage of carbon in the chalk ?

★ Solution :

↦ Parts of Calcium = 12%

↦ Parts of Carbon = 3%

↦ Parts of Sand = 10%

↦ Sum of ratio = 12 + 3 + 10 = 25

Percentage of carbon = parts of carbon / total parts × 100%

Now substitute the values :-

↦ % of carbon = 3 / 25 × 100%

↦ % of carbon = 3 / 5 × 20%

↦ % of carbon = 3 × 4%

↦ % of carbon = 12%

■ Hence, the percentage of carbon is 12%.