In each of these questions, a number series is given. In each series only one number is wrong. Find out the wrong number. $2 \quad 8 \quad 12 \quad 20 \quad 30 \quad 42 \quad 56$

The pattern is: +6, +4, +8, +10, +12, +14. This should be alternating +6, +4, then +8, +10, +12, +14 (even numbers starting from 6, but with 4 inserted). Starting from 2: 2+6=8✓, 8+4=12✓, 12+8=20✓, 20+10=30✓, 30+12=42✓, 42+14=56✓. Wait - all numbers fit! Let me re-examine. The pattern could be: +6, +4, +8, +10, +12, +14 (pairs of consecutive even numbers: 4+6=10, then 8+10=18, then 12+14=26 - not consistent). Actually, if we expect the pattern to be consecutive even differences, it would be +4, +6, +8, +10, +12, +14. With that pattern: 2+4=6 (not 8). So 8 is wrong - it should be 6.