*Answer is 12.8 days.*

32 men finish job in 32 days.----------> 1 mean finish job in 32*32 days.

so one men complete per day 1/(32 x 32) of work.

so 32 men in 8 days complete (32 x 8)/(32 x 32) of work ------> 1/4 of work -----> remaining work is 3/4.

now men is increased by 28 so now total men is 60.

now per day compeleted work is ------> 60 x work one men complete per day ------> 60/32 x32= 15 / 256

days need to finish the job = remining work / now per day compeleted work = (3/4)/(15 / 256) = *12.8 days*.