Question 1067620
I'm assuming that the 10 workers, working at
their normal rate would finish the job in exactly
8 days.
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The rate of working for 1 worker is:
[ 1/10 of the job ] / [ 8 days ] = [  1 job ] / [ 80 days ]
This is also [ 1/80 of the job ] / [ 1 day ]
In 2 days, the fraction of the job that gets done is:
{{{ 2*( 1/80 ) = 1/40 }}}
The leaves {{{ 39/40 }}} of the job left
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Now the rate has to be {{{ ( 39/40 ) / 2 = 39/80 }}} jobs/days
Let {{{ n }}} = the number of additional workers needed to
finish the job in 2 days
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{{{ ( 10 + n )*( 1/80 ) = 39/80 }}}
Multiply both sides by {{{ 80 }}}
{{{ 10 + n = 39 }}}
{{{ n = 29 }}}
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29 additional workers need to be added
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check answer: there is a total of {{{ 39 }}} workers to
do 39/40 of the job in {{{ 2 }}} days
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Each worker will do {{{ (1/39)*(39/40) = 1/40 }}} of the job in {{{ 2 }}} days
That is {{{ 1/80 }}} of the job in 1 day
This agrees with my original calculation
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Definitely try to get another opinion on this!