Answer:
approximately 7 days.
Step-by-step explanation:
Don takes time to complete 4 jobs = 3 days
he completed his job in 1 day = [tex]\frac{4}{3}[/tex]
Lily takes time to complete 5 jobs = 2 days
Lily completed her job in 1 day = [tex]\frac{5}{2}[/tex]
Working together they can complete the job in 1 day
= [tex]\frac{4}{3}+ \frac{5}{2}[/tex]
= [tex]\frac{8+15}{6}[/tex]
= [tex]\frac{23}{6}[/tex]
Working together it will take time to complete 25 jobs
= 25 ÷ [tex]\frac{23}{6}[/tex]
= [tex]25\times \frac{6}{23}[/tex]
= [tex]\frac{150}{23}[/tex]
= [tex]6\frac{12}{23}[/tex] days
= 6.52 ≈ 7 days
It will take 6.52 or approximately 7 days to complete 25 jobs together.
