As for the second question.
The answer should be 11 x 13 = 143 chairs
As Jaydon is sitting in one of the chair, on his left and right side got 5 chairs on each side,
there will be 10 + 1 (the one he’s sitting) = 11 chairs in each row.
And, infront and back got 6 chairs each,
there will be 12 + 1 (the one he’s sitting) = 13 rows.
Therefore, there will be 143 chairs altogether in the hall.