Bob has an unknown liquid and must determine what it is. he decides to systematically use a number of tests to determine the correct answer. what stage of cognitive development has bob reached?

The answer is formal operational. The formal operational stage starts at around age twelve and keeps going into adulthood. Amid this time, individuals build up the capacity to consider conceptual ideas. Abilities, for example, intelligent thought, deductive thinking, and precise arranging likewise rise amid this stage.