Select the option that is related to the third number in

In each of the following number series, one term is missing. Find the missing term.

5, 10, 20, 40, ?, 160

16.12 × 15.94 + 654.92 – 344.83 = ?× 5.95

What will come in place of the question mark (?) in the following series?

68, 76, 61, 85, ?, 98

In each of the following series, one term is missing. Find the missing term.

5, 13, 29, 61, 125, ?

81, 41, 42, 64.5, ?, 330

10, ?,  50, 100, 250, 500

(10² × 24)/8 = ?

What will come in place of (?) Question mark in the given number series.

500, 489, 467, 434, 390, 335, ?

3, 8, 27, 124, ?

6, 7, 16, 51, 208, ?