Let the total number of trees be \(7u\) (apple \(3u\), orange \(4u\)).

• Apple trees bearing fruit = \(\frac{5}{5+1} \times 3u = \frac{5}{6} \times 3u = 2.5u\).
• Orange trees bearing fruit = \(\frac{7}{7+1} \times 4u = \frac{7}{8} \times 4u = 3.5u\).
• Total bearing fruit = \(2.5u + 3.5u = 6u\).
• Percentage bearing fruit = \(\frac{6u}{7u} \times 100\% = 85.7142...\% \approx 85.71\%\) (to 2 decimal places).

Final Answer: 85.71%