Farina wrote:
sandy wrote:
Explanation
Each term in the sequence is 9 greater than the previous term. To make this clear, write a few terms of the sequence: 11, 20, 29, 38, etc.
a_{35} comes 34 terms after a_1 in the sequence. In other words, a_{35} is 34 \times 9 = 306 greater than a_1.
Thus, a_{35} = 11 + 306 = 317.
Why did you add 11?
The formula is Tn = a + (n-1)d, a = first term, n = term to find, d = difference between two consecutive terms (since 9 is added with every term, that is the difference)
Where T35 = 11 + (35-1) 9
T35 = 11 + (34) 9
T35 = 317