To calculate the adjusted profit before tax that reflects core performance, we need to remove non-recurring items and adjust for recurring items that may not reflect ongoing operations.

Calculation:

• Start with Profit before tax: €30 million
• Remove one-off income from associates and joint ventures: -€10 million (non-recurring)
• Add back one-off revaluation loss: +€4 million (non-recurring)
• Remove recurring provisions for restructuring: -€3 million (recurring but may not reflect core operations)

Adjusted PBT = €30 - €10 + €4 - €3 = €27 million

The €27 million best reflects the company's core performance by excluding non-recurring items and adjusting for recurring items that may distort the true ongoing performance.