(i) Chalk contains calcium, carbon and oxygen in the ratio 10:3:12. Find the percentage of carbon in chalk.(ii) If in a stick of chalk, carbon is 3g, what is the weight of the chalk stick?

Explanation

To solve the problem step by step, we will break it down into two parts as given in the question.

### Part (i): Find the percentage of carbon in chalk.

1. **Identify the ratio components**: The ratio of calcium, carbon, and oxygen in chalk is given as 10:3:12. Here, the component representing carbon is 3.

2. **Calculate the total parts in the ratio**:
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