Correct Answer - Option 3 : 3
Immediately preceded by means immediately before or to come just before.
Immediately followed by means immediately after or to come just after.
The pattern followed here is:
Condition to be checked:
i) 8's are neither immediately followed nor immediately preceded by 7.
Not 7 → 8 → Not 7
Given Series: 78452438619687875968831487278
8's which are neither immediately followed nor immediately preceded by 7 → 78452438619687875968831487278
⇒ there are three such 8's.
Hence, 3 is the correct answer.
