Problem Solving

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.

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

baller12q wrote: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.

baller12q wrote: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.

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