Q. 8, 11, 21, 15, 18, 21, 22, ... choose which pair of numbers comes next?
✅ Correct Answer: (B)
25, 21
Explanation: This is an alternating addition series, with a random number, 21, interpolated as every third number. The addition series alternates between adding 3 and adding 4. The number 21 appears after each number arrived at by adding 3.
Explanation by: Ritu Singhal
This is an alternating addition series, with a random number, 21, interpolated as every third number. The addition series alternates between adding 3 and adding 4. The number 21 appears after each number arrived at by adding 3.