Find out the wrong number in the series - 10, 26, 74, 218, 654, 1946, 5834

Answer 1

654

Each term is 4 less than thrice the preceding number.
So, 654 is wrong and must be replaced by (218 * 3 - 4) = 650.

Answer 2

This series is developed as follows:
. 10
. 10*3= 30 - 4 = 26 (26)
. 26*3=78 - 4 = 74 (74)
. 74*3 = 222-4=218 (218)
. 218*3= 654-4 = 650 (654)
. 650*3=1950-4=1946 (1946)
. 1946*3=5838-4= 5834 (5834)
As you can see, 654 is the wrong number