work problem

[baller12q]

Each of 10 machines works at the same constant rate doing a certain job. The amount of time neeeded by the 10 machines, working together, to complete the job is 16 hours. How many hours would be needed if only 8 or the machines, working together, were used to complete the job.


i got this one wrong, can someone help me with this one.

[Neo2000]

Each machine is working for 16hrs.
So total work done = 10 x 16 = 160 machine hours

Now you have 8 machines to do a total of 160 machine hours
How long will they take??
160/8 = 20hours

[schowdhary]

Each of 10 machines works at the same constant rate doing a certain job. The amount of time neeeded by the 10 machines, working together, to complete the job is 16 hours. How many hours would be needed if only 8 or the machines, working together, were used to complete the job.


i got this one wrong, can someone help me with this one.

I also agree with the answer that it will take 20 hours to do the same work. Please post the correct answer.

[vittalgmat]

Each of 10 machines works at the same constant rate doing a certain job. The amount of time neeeded by the 10 machines, working together, to complete the job is 16 hours. How many hours would be needed if only 8 or the machines, working together, were used to complete the job.


i got this one wrong, can someone help me with this one.

Ballerq,
As I mentioned in an earlier post. Pls post the answer choices and the OA in a spoiler either by clicking the spoiler button once, type the answer and then click spoiler again or typing the spoler tag explicitly.

[baller12q]

sorry about not putting the anwsers im new to this and thanks for helping me