We have:
row 1 = 1
row 2 = 3
row 3 = 5
Then, the sequence is given by:
[tex]a_{n=}2n-1[/tex]Then, to determine the row with 900 blocks we use the following formula:
[tex]S_n=n(\frac{a_1+a_n}{2})[/tex]Where: Sn = 900, an = 2n-1 and a1 = 1
[tex]900=n(\frac{1+2n-1}{2})[/tex]And solve for n (the number of rows):
[tex]\begin{gathered} 900=n(\frac{2n}{2}) \\ 900=n(n) \\ 900=n^2 \\ \sqrt[]{900}=n \\ n=30 \end{gathered}[/tex]Answer: 30 rows
