the answer is 36, their are 6 sides to a die, and your rolled it 5 times so multiply those 2 (6x5) which equals 30 so then add 6 because their is 6 sides and that equals 36. its so easy what don't you understand.
t1 = 2d.
the explicit formula for an arithmetic series is
the nth term tn = t1 + d(n - 1) where t1 = the first term , d = common difference and n = term number.
so t17 = t1 + 17d - d = t1 + 16d
and t5 = t1 + 5d - d = t1 + 4d
so t1 + 16d = 3(t1 + 4d)
2t1 = 16d - 12d = 4d
t1 = 2d (answer).