The number of hours needed to assemble computers varies directly as the number of computers and inversely as the number of workers. If 4 workers can assemble 12 computers in 9 hours, how many workers are needed to assemble 48 computers in 8 hours

18 workers

4 workers can assemble 12 computers in 9 hours.

Since the number of hours is directly proportional to the number of computers:

4⋅12=48 computers could be assembled by 4 workers in 4⋅9=36 hours.

Since the number of hours is inversely proportional to the number of workers:

48 computers could be assembled by 92⋅4=18 workers in 29⋅36=8 hours.