Answer:
4 workers
Step-by-step explanation:
A group of 9 workers was assigned to paint the walls in a house, which could be completed in 48 hours. Then 1 worker will complete the whole job in [tex]48\times 9=432[/tex] hours.
If 1 worker completes the whole work in 432 hours, then he completes [tex]\dfrac{1}{432}[/tex] of the work per hour.
9 workers complete [tex]9\times\dfrac{1}{432}=\dfrac{1}{48}[/tex] of work per hour and complete [tex]\dfrac{1}{48}\times 8=\dfrac{1}{6}[/tex] of work in 8 hours.
[tex]1-\dfrac{1}{6}=\dfrac{5}{6}[/tex] of work left.
This could be completed by n workers in 72 hours, so
[tex]\dfrac{n}{432} \times 72=\dfrac{5}{6}\\ \\\dfrac{n}{6}=\dfrac{5}{6}\\ \\n=5[/tex]
9 - 5 = 4 workers left the team.
