[填空题]
The table shows the fir mn)hcjr0 d11qm ,m-dj s4olbgw *gptzj8 82w//4sd axst four terms of three sequences: $u_n$ , $v_n$ , and $w_n$.
1.State which sequence is
1.1.arithmetic is ;
1.2.geometric is .
2.Find the sum of the first 50 terms of the arithmetic sequence.
$S_{50}$= .
3.Find the exact value of the 13th term of the geometric sequence