posted by Anonymous .
it takes 7 men 10 days to build a garage.Halfway through building the garage they get some help from 3 people and continue to work at the same rate
a)How long will it take to finish of the garage
b)How long did it take
7*10 man days
After 5 days or 35 man days
there are now 10 men to do 35 man days of work
35/10=3.5 days to finish the work for a total of 8.5 days