The characteristics of two types of solid waste are given in the table.
| Type of solid waste | Moisture content (%) | Nitrogen content (%) | Carbon to Nitrogen (C/N) ratio |
|---|
| Leaves | 50 | 0.7 | 50 |
| Sludge | 75 | 5.6 | 6.3 |
The quantity of sludge to be added to leaves to achieve a C/N ratio of 25 (on dry basis) for the mixed waste is ______ kg of sludge/kg of leaves (rounded off to three decimal places).