SOLUTION: A professor can grade three tests in the time it takes a student assistant to grade one test. Working together, they can grade the tests for a class in 2 hours.How long would it ta

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A professor can grade three tests in the time it takes a student assistant to grade one test. Working together, they can grade the tests for a class in 2 hours.How long would it ta      Log On


   



Question 1137052: A professor can grade three tests in the time it takes a student assistant to grade one test. Working together, they can grade the tests for a class in 2 hours.How long would it take the student assistant working alone?
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!

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r, rate of student assistant
3r, rate of professor
The quantity of tests to grade is 1 job.
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%28r%2B3r%292=1
2%2A4r=1
highlight%28r=1%2F8%29------------------ 1 job in 8 hours, the student assistant.

Answer by ikleyn(52805) About Me  (Show Source):
You can put this solution on YOUR website!
.
I solved today very similar problem (a TWIN). See the link

https://www.algebra.com/algebra/homework/word/misc/Miscellaneous_Word_Problems.faq.question.1137025.html

https://www.algebra.com/algebra/homework/word/misc/Miscellaneous_Word_Problems.faq.question.1137025.html

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It is a standard and typical joint work problem.

There is a wide variety of similar solved joint-work problems with detailed explanations in this site.  See the lessons
    - Using Fractions to solve word problems on joint work
    - Solving more complicated word problems on joint work
    - Selected joint-work word problems from the archive


Read them and get be trained in solving joint-work problems.

Also,  you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this textbook under the topic
"Rate of work and joint work problems"  of the section  "Word problems".


Save the link to this online textbook together with its description

Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson

to your archive and use it when it is needed.