Final answer:
To complete the letter series, the set of letters 'uv', 'xy', and 'zw' should be sequentially placed at the gaps in the given series 's ut vwu wx vw y'.
Step-by-step explanation:
The given letter series is: s ut vwu wx vw y
To complete the letter series, we need to find the set of letters that should be sequentially placed at the gaps. By analyzing the letters in the given series, we can observe that the letters follow a pattern. The pattern is formed by taking the second and third letters from each chunk of three consecutive letters and placing them in the next chunk.
Applying this pattern to the given series, we can complete it by adding the letters 'uv' at the first gap, 'xy' at the second gap, and 'zw' at the third gap. Therefore, the completed letter series is: s ut vwu wx vw yzwxvyzw.