1. What is the probability of randomly chosen bit to arrive undistorted?

A self-correcting algorithm is applied adding 4 additional bits to each 3-bit "character"(see* Hamming * on the web). The new block is transmitted through the same faulty media, decoded to get the message only and the same question is asked:

2.What is the probability of randomly chosen bit to arrive undistorted?

Rem: If solved by simulation, define the achieved accuracy. Your ideas about improving the "reliability figure" will be welcome.