Multiple choice

Find the wrong term in the give number series questions.. 1 3 6 11 20 39 70

  1. 3

  2. 39

  3. 11

  4. 20

  5. 6
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Analyzing the pattern: 1→3 (×2+1), 3→6 (×2), 6→11 (×2-1), 11→20 (×2-2), 20→39 (×2-1), 39→70 (×2-8). The pattern isn't consistent. Let's try differences: 2, 3, 5, 9, 19, 31. Second differences: 1, 2, 4, 10, 12. 39 breaks the pattern - the terms after 11 should follow ×2-1: 11→21→41. Actually, from 20 the next should be 20×2-3=37, then 37×2-3=71. So 39 is wrong.

Keep practicing — related questions