Multiple choice general knowledge math & puzzles

7,26,63,124,215,342,?

  1. 481

  2. 511

  3. 391

  4. 421
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pattern is n³ - 1 where n increases by 1 starting from 2: 2³-1=7, 3³-1=26, 4³-1=63, 5³-1=124, 6³-1=215, 7³-1=342. The next term is 8³-1=511. Option A (481) would be from subtracting 139, C (391) from subtracting 49, and D (421) from subtracting 79 - none follow the cubic pattern.

AI explanation

To find the pattern in the given sequence, let's look at the differences between consecutive terms:

26 - 7 = 19 63 - 26 = 37 124 - 63 = 61 215 - 124 = 91 342 - 215 = 127

We can notice that the differences between consecutive terms are increasing by 18 each time: 19, 37, 61, 91, 127.

Now, let's look at the second differences:

37 - 19 = 18 61 - 37 = 24 91 - 61 = 30 127 - 91 = 36

We can see that the second differences are increasing by 6 each time: 18, 24, 30, 36.

So, based on this pattern, we can predict that the next second difference would be 42 (36 + 6).

Now, let's calculate the next difference:

127 + 42 = 169

And finally, let's add this difference to the last term in the sequence:

342 + 169 = 511

Therefore, the next term in the sequence is 511.

Comparing this with the given options: A) 481 - Incorrect B) 511 - Correct C) 391 - Incorrect D) 421 - Incorrect

The correct answer is option B) 511.

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