Решение:
Пусть x - искомое число. Тогда
\(x - 2\frac{5}{8} = 8\frac{11}{16} - 3\frac{31}{32}\)
\(x - 2\frac{5}{8} = 8\frac{22}{32} - 3\frac{31}{32}\)
\(x - 2\frac{5}{8} = 7\frac{54}{32} - 3\frac{31}{32}\)
\(x - 2\frac{5}{8} = 4\frac{23}{32}\)
\(x = 4\frac{23}{32} + 2\frac{5}{8}\)
\(x = 4\frac{23}{32} + 2\frac{20}{32}\)
\(x = 6\frac{43}{32} = 7\frac{11}{32}\)
Ответ: \(7\frac{11}{32}\)