Look at the series: F2, ___, D8, C16, B32. What should fill the blank?

What should come in place of ? in the following series ? 117, 98, 80, 64, ?, 42

What should come in place of question mark (?) in the following number series? 132 156 ? 210 240 272

What will be the next number in the following number series? 48, 24, 72, 36, 108, ?

What will come in place of question mark (?) in the series X5C, U8F, ?, O17L, L23O?

Which number should replace ‘?’ in the following series? 240, 120,? , 180, 360, 900