This is the technique of using your opponents young age to say that he is not qualified.
It show the reader how different types of moods are portrayed through out the poem.
From bad, through competent and good to great, and the classification is seemingly well-defined and mostly outside our control. I read this in my English book about a week ago. Hope this answer helps and mark as.
12.5% of 64 is 8. This is equivalent to 1/8 of 64 as well