Question 1138502
"one teacher", same as "first teacher", {{{1/50}}} stack per minutes
Other teacher, {{{1/100}}} stack per minutes


First teacher works for 23 minutes and then both teachers work together for x minutes, in order to grade 1 stack of papers.


{{{(1/50)*23+(1/50+1/100)*x=1}}}
Simplify and solve for x.


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{{{23/50+(2/100+1/100)x=1}}}

{{{46/100+3x/100=1}}}

{{{46+3x=100}}}

{{{3x=54}}}

{{{highlight(x=18)}}}
The two work together for 18 minutes.
Total time doing the grading was 23+18=41 minutes.