Which of the following is NOT a common synchronization

11     46     109     208      351       ?

Compute Σ (1 / (k(k+1))) from k = 1 to 10.

11      28       47       70      ?        130

94, 563, 2813, ? 33743, 67481

19    20    42    129    ?      2605   .  

6           5           40            32                 249                   240

35, 36, 40, 49 , 65 , ?

45       47       97       296       ?       5966

There are 3 series, you have to find value of a, b, c and then establish relation among a,b,c.

19, 25, 45, a, 553, 2767

69       119       156       ?       199       209