Find out the wrong number in the number series given below. $105 \quad 85 \quad 60 \quad 30 \quad 0 \quad -45 \quad 90$

The series follows the pattern: -20, -25, -30, -30, -45, +135... Starting from 105: 105-20=85, 85-25=60, 60-30=30, 30-30=0, 0-45=-45, -45+135=90 (not required for pattern). The term 0 fits the pattern as 30-30=0. However, looking more carefully at the pattern of subtracting increasing multiples of 5: 105-20=85, 85-25=60, 60-30=30, 30-30=0. The pattern breaks here - the next subtraction should be -35, not -30. So 0 is wrong (should be -5). Option A (0) is correct.