Step-by-step explanation:
Let w be the work and r be the rate at which one machine is doing the work.
The amount of time needed by the 10 machines, working together, to complete the job is 16 hours.
Work done by machine = Number of machines x Rate at which one machine is doing the work x Time
w = 10 x r x 16
[tex]r=\frac{w}{160}[/tex]
Now we need to find time taken t by 8 machines to the same work.
Work done by machine = Number of machines x Rate at which one machine is doing the work x Time
w = 8 x r x t
[tex]w=8\times \frac{w}{160}\times t\\\\t=\frac{160}{8}=20hours[/tex]
Time taken 8 machines to the same work = 20 hours
Option B is the correct answer.
