Find the missing term in the series: \[ X,\ U,\ S,\ P,\ N,\ K,\ \underline{\hspace{1cm}} \]
Find the missing term in the series: \[ 8,\ 18,\ 38,\ 78,\ 158,\ 318,\ \underline{\hspace{1cm}} \]
Find the missing term in the series:
\[ 2,\ 6,\ 20,\ 42,\ 110,\ 156,\ \underline{\hspace{1cm}} \]
Find the missing pair: \[ (8,24),\ (48,120),\ (168,288),\ (360,528),\ \underline{\hspace{2cm}} \]
Find the missing term in the series: \[ 1,\ 2,\ 6,\ 15,\ 31,\ 56,\ \underline{\hspace{1cm}} \]
Find the missing term in the series: \[ \text{AB2},\ \text{EE3},\ \text{IH5},\ \text{OK7},\ \text{UN11},\ \text{AQ13},\ \underline{\hspace{1cm}} \]
Find the missing term in the series: \[ 3,\ 7,\ 13,\ 19,\ 29,\ 37,\ \underline{\hspace{1cm}} \]
Find the missing term in the series: \[ 8,\ 18,\ 38,\ 78,\ 148,\ 258,\ \underline{\hspace{1cm}} \]