Discussion

Insert the missing number 8, 7, 11, 12, 14, 17, 17, 22, (....)

Answer: B

Two series are interleaved.

\[ \text{positions 1, 3, 5, 7, 9: } 8,\; 11,\; 14,\; 17,\; \mathbf{20} \quad (+3) \]

\[ \text{positions 2, 4, 6, 8: } 7,\; 12,\; 17,\; 22 \quad (+5) \]

The ninth term belongs to the first series:

\[ 17 + 3 = 20 \]

Continuing the second series instead would give 27, which is offered as the first option.

No comment is present. Be the first to comment.

Loading…