If the ratio of areas of two circle is 4:25, then the

58      83      133      ?       308       433

60, 100, 160, 240, ?, 460

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

7, 14, 28, 56, 112, ?

12, 19, 33, ?, 117

4, 12, 36, 108, ?, 396

945, 1890, ?, 504, 144, 32

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

11, 13, 19, ?, 51, 81

Find the missing number, in the given number series.

60, 150, ?,  450, 450, 225

31      40      51      64      79       ?