{"id":8958,"date":"2016-04-21T14:41:24","date_gmt":"2016-04-21T14:41:24","guid":{"rendered":"http:\/\/www.manhattanprep.com\/gre\/?p=8958"},"modified":"2019-08-30T16:39:14","modified_gmt":"2019-08-30T16:39:14","slug":"a-step-by-step-guide-to-multiple-workers-gre-rates-problems","status":"publish","type":"post","link":"https:\/\/www.manhattanprep.com\/gre\/blog\/a-step-by-step-guide-to-multiple-workers-gre-rates-problems\/","title":{"rendered":"A Step-by-Step Guide to ‘Multiple Workers’ GRE Rates Problems"},"content":{"rendered":"

\"ManhattanDid you know that you can attend the first session of any of our online or in-person GRE\u00a0courses absolutely free? We\u2019re not kidding! Check out our upcoming courses here<\/a>.<\/strong><\/em><\/p>\n

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Nine identical machines, each working at the same constant rate, can stitch 27 jerseys in 4 minutes. How many minutes would it take 4 such machines to stitch 60 jerseys?<\/em><\/p>\n

First, take a deep breath. In this article, you’ll learn a methodical approach that will work on GRE rates problems\u00a0every single time. On test day, it’ll be tempting to throw away your new habits and go back to old ones. Try to do the opposite. You’ve done all of this studying for a reason!<\/p>\n

On problems like this, don’t try anything fancy. A lot of GRE test-takers will try to logically reason their way through this problem, saying something like “well, if 9 machines stitch 27 jerseys in 4 minutes, then 3 machines stitch 9 jerseys in 12 minutes…” That approach is valid but dangerous. Whenever you choose not to write something down, you’re taking away your ability to check your work for mistakes. (By the way, where’s the mistake in the logic described above?)<\/p>\n

To start the problem, make a table. Your scratch paper should look like this:<\/p>\n

\"Manhattan
\nUsing the table, figure out how quickly a single machine is working. Solve the equation 9 * ? * 4 = 27 to learn that ?, the unknown value, equals 3\/4. Add it to the table.<\/p>\n

Once the first line is completely filled in, add a second line with the remaining information:<\/p>\n

\"Manhattan<\/strong><\/p>\n

Finally, solve for the unknown value. <\/strong>In this case, we’re looking for the time. Solve the equation 4 * 3\/4 * ? = 60 to find that ? equals 20. The answer is 20 minutes.<\/p>\n

If you’re creating a cheat sheet<\/a> for GRE Rates & Work problems, add the steps that we took to solve this one:<\/p>\n