Answer:
The answer to your question is: spend 6 hours eating pizza
Explanation:
Data
training = 8 h
eating pizza = 3 h
10 more hours training than eating
hours eating pizza = ?
Process
hours eating pizza = p
hours training = p + 10

8p = 3(10 + p)
8p = 30 + 3p
8p - 3p = 30
5p = 30
p = 30/5
p = 6 hours