This question will get closed in stackexchange very soon because they don’t allow such questions there. So please answer it here. Only hardcore computer scientists can answer this as this is bit tougher concept to explain.So only bsc.csit students can answer this. This isn’t for any other computer degree students imo.
Not a computer scientist, but trying to help on 1st and 2nd query.
The C is already defined read_time/word thus you don’t have to mention as nmfc/(word). I guess that’s the problem.
Ea = Serial Time / p * Tp
The total time that is required to read number of words from all document is nmfc and multiple processor handle in nmfc/p time. So each processor takes same time which is nmfc/p. But Tp is total time taken in parallel, thus Tp = pnmfc/p.
Ea = nmfc/(p * Tp)