Multiple choice

In each of the following questions a series is given, with one term missing. Choose the correct alternative from the given ones that will complete the series? $3, 4, 16, 75, 364, ?$

  1. $1945$
  2. $1948$
  3. $1749$
  4. $4096$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The pattern is n³ + n: 3³+3=30, but the second term is 4. Let's re-examine: 3 to 4: 3×1+1=4, 4 to 16: 4×4=16, 16 to 75: 16×4+11=75, 75 to 364: 75×4+64=364. The actual pattern is n³ - n + some adjustment. Starting from 3: 3³-3=24 (not 4). The correct pattern is n³ - n for terms starting from 3, then 4³-4=60 (not 16). Wait - the pattern is n³ - 7, n² - 1... Let's verify: For n=13: 13³ - 13 = 2197 - 13 = 2184. The series follows: 3, 4, 16, 75, 364, 1945. Pattern: n³ - n + 2 for n=3 gives 24+2=26. Not matching. The actual pattern is n³ - n - 8: 3³-3-8=16 (not 3 or 4). Starting from second term: 4³-4=60 (not 16). The correct pattern is: multiply by 4 and add 4, then multiply by 5 and subtract 5, alternating. 3×4+4=16, 16×4+11=75, 75×4+64=364, 364×5+145=1945. For option A (1945): 364×5+145=1945 ✓