Which completes the series 2, 3, 5, 8, 13, ?

Which completes the series 2, 3, 5, 8, 13, ?

• A. 18
• B. 21
• C. 24
• D. 26

Answer: (B)

The pattern is that each term is the sum of the two previous ones. Starting with 2 and 3, the sequence goes 2, 3, 5 (2+3), 8 (3+5), 13 (5+8). The next term is 8 + 13 = 21, so the missing number is 21. The other options don’t follow this rule because they aren’t the sum of the two immediately preceding numbers.

The pattern is that each term is the sum of the two previous ones. Starting with 2 and 3, the sequence goes 2, 3, 5 (2+3), 8 (3+5), 13 (5+8). The next term is 8 + 13 = 21, so the missing number is 21. The other options don’t follow this rule because they aren’t the sum of the two immediately preceding numbers.