Question

Look at this series: q1f, s2e, u6d, w21c, , ... what number should fill the blank?

Answer 1

Answer:

Y88B

Step-by-step explanation:

The first letter of each term is moved two steps forward and  the last letter is moved one steps backward to obtain the corresponding letters of the next term.

The number series runs as follows :

1 x 1 + 1 = 2,

2 x 2 + 2 = 6,

6 x 3 + 3 = 21,

21 x 4 + 4 = 88.