Question 1206760
work rate each worker, r
n, expected how many workers


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A contractor undertook to do a certain piece of work in 9 days. He employed certain number of men, 
but 6 of them being absent from the very first day, the rest could finish the work in 15 days.
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{{{n*r*9=1}}}
{{{and}}}
{{{r(n-6)*15=1}}}


{{{9nr=15r(n-6)}}}
-
{{{9n=15(n-6)}}}

{{{9n=15n-90}}}

{{{90=6n}}}

{{{highlight(n=15)}}}