Final answer:
Spartan boys spent approximately 13 years in the agoge, starting from the age of seven and completing the training at the age of twenty.
Step-by-step explanation:
Spartan boys began their education in the agoge at the age of seven. This rigorous training program was central to Spartan culture and was designed to produce disciplined and skilled warriors. The boys were put through extreme physical and military training, including regular beatings and being fed minimally, which forced them to steal food to survive.
At the age of twelve, they faced even harsher conditions, such as being allowed to wear only a single cloak through the year and bathing just once annually. At eighteen, they underwent two years of intense military preparation. By the age of twenty, the Spartan young men completed their agoge education and were considered ready for full military duty and to become full citizens as "Equals" if deemed worthy.