You cant answer the Question with out the picture <span />
If you assume doubling the workers will halve the time taken to finish then 12 analysts will take 21 days
To finish in 7 days (1/6 of 42 days) you would need 6 x the original number = 36 analysts.
Brook’s Law (see Wikipedia) suggests than adding extra analysts will actually slow the project down!
One reason is the extra people tend to get in each others way.
I think it's 1/2 because 5/10= 1/2
I hope this helps!
