Answer:
It would take 7.62 minutes for the third conveyor belt alone to do the same job
Step-by-step explanation:
The together rate is the sum of each separate rate.
In this question:
First conveyor: Rate of 1/9.
Second: Rate of 1/11.
Third: Rate of 1/x.
Total: 1/3
So
[tex]\frac{1}{9} + \frac{1}{11} + \frac{1}{x} = \frac{1}{3}[/tex]
[tex]\frac{11x + 9x + 99}{99x} = \frac{1}{3}[/tex]
[tex]\frac{20x + 99}{99x} = \frac{1}{3}[/tex]
[tex]3(20x + 99) = 99x[/tex]
[tex]60x + 297 = 99x[/tex]
[tex]39x = 297[/tex]
[tex]x = \frac{297}{39}[/tex]
[tex]x = 7.62[/tex]
It would take 7.62 minutes for the third conveyor belt alone to do the same job
