An information source produces binary triplets $\{000,111,010,101,001,110,100,$

$0116\}$ with corresponding probabilities $\{1/4,1/4,1/8,1/8,1/16,1/16,1/16,1/16\}.$

A binary code assigns a codeword of length $$ log$2$

$($pk$)$ to triplet number k$.$ Let X be

the length of the output codeword.