Select the INCORRECTLY spelt

800 400 600 1500 ? 23625

13 15 ? 63 143 293

If 18 x 10 42 -22,

Then, 50% of 2x - 25% of x = ?

Identify the logic of the below given series and given answer.

Series I :: 81, 89, 116, 241, (A), 1915

21, 37, 62, 98, 147, ?

Complete the series.

19, 23, 26, 30, 33, ?

8, 9, 15, ?,82.5, 250.50

7, 14, 42, 210, 1470, ?

Select the number from among the given options that can replace the question mark (?) in the following series.

2, 6, 12, 20, ?, ?

If  2,   7,  20,   x ,   110,    235,

Then,  7 x + 7√x = ?