How many 'S' are there in the following series that come immediately before K and immediately after K ?
$$\text{S S K S K S R K S P O K S K S K S}$$

The question asks for the count of the letter 'S' which satisfies two conditions simultaneously: it comes immediately before K (meaning $\text{S}$ is followed by $\text{K}$) AND immediately after K (meaning $\text{S}$ is preceded by $\text{K}$).
This implies we are searching for the pattern "K S K".

Let's look at the given sequence:

$$\text{S S K S K S R K S P O K S K S K S}$$

Highlighting the "K S K" patterns:

1. $\text{S S K S K S R K S P O K S K S K S}$
2. $\text{S S K S K S R K S P O K S K S K S}$
3. $\text{S S K S K S R K S P O K S K S K S}$

There are exactly $3$ such occurrences where an 'S' is sandwiched between two 'K's.