What is prime triplet?

Answer 1

Apart from {2,3,5} and {3,5,7} prime triplets are sets of the from {n, n+2, n+6} or {n, n+4, n+6} such that each of the three numbers in the set are primes.

Note that {n, n+2, n+4}, three alternate [odd] numbers cannot all be primes since one of them must be divisible by 3.