Multiple choice

A number series is given below with one number missing, shown by a ''?''. Choose from the options the correct alternative that will fit the pattern of the series. 4, 9, 19, ?, 79, 159

  1. 59

  2. 33

  3. 39

  4. 34
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The pattern is: 4*2+1=9, 9*2+1=19, 19*2+1=39, 39*2+1=79, 79*2+1=159. The missing number is 39.

AI explanation

The pattern multiplies each term by 2 and adds 1 to get the next term. For example, 4 times 2 is 8 plus 1 is 9, and 9 times 2 is 18 plus 1 is 19. Applying this to 19, we get 19 times 2 is 38 plus 1 is 39. We verify this because 39 times 2 is 78 plus 1 is 79. The missing number is 39.

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