please solve it

2.10. Consider the vectors { (1, 12, 13, TA, Is, $6) : I; 2 0, I, integer}. The following are separate questions: (a) How many of these vectors have _ I; = 10? (b) How many of these vectors have __I; = 10 and ~] = 12 = 13 = 1? (c) How many of these vectors have _ I; = 10 and ~] = 12 = 13