The weight of 12 sheets of a thick paper is 40 grams . How many sheets would weigh 1 kg?

Options

A. 480
B. 360
C. 300
D. non of these

Answer

To solve the problem step by step, we will use the concept of direct proportion.

### Step-by-Step Solution:

1. **Understand the Given Information**:
We know that the weight of 12 sheets of thick paper is 40 grams.

2. **Convert 1 kg to grams**:
Since we need to find out how many sheets weigh 1 kg, we first convert 1 kg to grams:
\[ 1 \text{ kg} = 1000 \text{ grams} \]

3. **Set Up the Proportion**:
We can set up a proportion based on the information given. If 12 sheets weigh 40 grams, we can express this relationship as:
\[ \frac{\text{Number of sheets}}{\text{Weight in grams}} = \frac{12 \text{ sheets}}{40 \text{ grams}} \]

4. **Find the Number of Sheets per Gram**:
We can find out how many sheets correspond to 1 gram:
\[ \text{Sheets per gram} = \frac{12 \text{ sheets}}{40 \text{ grams}} = \frac{12}{40} = \frac{3}{10} \text{ sheets per gram} \]

5. **Calculate the Number of Sheets for 1000 grams**:
Now, to find out how many sheets weigh 1000 grams, we multiply the number of sheets per gram by 1000:
\[ \text{Number of sheets in 1000 grams} = \left(\frac{3}{10} \text{ sheets/gram}\right) \times 1000 \text{ grams} = 300 \text{ sheets} \]

6. **Conclusion**:
Therefore, the number of sheets that would weigh 1 kg (1000 grams) is **300 sheets**.

### Final Answer:
The answer is **300 sheets**.