Understanding the Problem
To find the cost of 12 pens, we first need to determine the cost of 1 pencil and then use that information to find the cost of 12 pencils.
Step 1: Calculate the Cost of One Pencil
- Given that the cost of 9 pencils is Rs 72:
- Cost of 1 pencil = Total cost / Number of pencils
- Cost of 1 pencil = 72 / 9 = Rs 8
Step 2: Calculate the Cost of 12 Pencils
- Now that we know the cost of one pencil, we can find the cost of 12 pencils:
- Cost of 12 pencils = Cost of 1 pencil * Number of pencils
- Cost of 12 pencils = 8 * 12 = Rs 96
Step 3: Determine the Cost of 8 Maths
- According to the problem, the cost of 12 pencils equals the cost of 8 maths:
- Therefore, cost of 8 maths = Rs 96
Step 4: Cost of 1 Maths
- To find the cost of one maths:
- Cost of 1 maths = Total cost of maths / Number of maths
- Cost of 1 maths = 96 / 8 = Rs 12
Step 5: Cost of 12 Pens
- The final step is to find the cost of 12 pens. However, the problem does not provide any specific information about the cost of pens. If we assume that the cost of 1 pen is the same as the cost of 1 maths (Rs 12), we can calculate:
- Cost of 12 pens = Cost of 1 pen * Number of pens
- Cost of 12 pens = 12 * 12 = Rs 144
Conclusion
The cost of 12 pens, assuming they are priced the same as maths, is Rs 144.