If adenine is 31% in DNA, calculate the percentage of cytosine. Explain briefly.
Adenine pairs with thymine (31% each), totaling 62\%. Cytosine and guanine share the remaining 38%. Therefore, cytosine is 19%, following Chargaff’s rule, where purines (adenine, guanine) always pair with pyrimidines (thymine, cytosine).

| S. No. | Particulars | Amount (in ₹ crore) |
|---|---|---|
| (i) | Operating Surplus | 3,740 |
| (ii) | Increase in unsold stock | 600 |
| (iii) | Sales | 10,625 |
| (iv) | Purchase of raw materials | 2,625 |
| (v) | Consumption of fixed capital | 500 |
| (vi) | Subsidies | 400 |
| (vii) | Indirect taxes | 1,200 |