166        156       136      ?     

7, 9, 21, ?, 107, 197

(14.073)² + (32.103)² + (43.9653)² + (52.983)² + ? = (102.45)² + (98.007)²

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

124, 131, 117, ?, 110, 145

92, 88, 79, ?,  38, 2

31      40      51      64      79       ?

58, 63, 78, ?, 138, 183

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

47, 56, 120, 145, ?, 410

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

40, 25, 30, 50, 105, ?

5 6 14 45 ? 925

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

15, 90, 450, ?, 5400, 10800