What is the 20th term of the arithmetic sequence 8,21,34,47,

Well considering that

F (1) = 8

F (x) = f(x-1) + 13

(Meaning the previous term plus 13)

So

F (x) = 13x - 5

F (0) = -5

well there are two answers for that.

1: you need 120 ones then that will equal up to 120.

2: you could also do one 100 and 2 tens.

those are the answers that i have thought of.