Find the wrong number of the series.
6400, 3200, 1600, 600, 400, 200, 100, 50
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 600
Each term is half of the term before it:
6400 → 3200 → 1600, each halved
Half of 1600 is 800, but the series has 600
800 → 400 → 200 → 100 → 50, each halved again
The term after 600 is 400, which is half of 800, not of 600; so 600 is the wrong number.