Question 1156190
Add their rates of working
Let {{{ t }}} = time in minutes to 
finish job working together
{{{ 1/15 + 1/30 = 1/t }}}
Multiply both sides by {{{ 30t }}}
{{{ 2t + t = 30 }}}
{{{ 3t = 30 }}}
{{{ t = 10 }}} min
The whole job gets done in {{{ 10 }}} min
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To get the fraction of the job done by worker 1:
{{{ 1/15 = x/10 }}}
{{{ 2 = 3x }}}
{{{ x = 2/3 }}}
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To get the fraction done by worker 2:
{{{ 1/30 = y/10 }}}
{{{ 1 = 3y }}}
{{{ y = 1/3 }}}
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Worker 1 does 2/3 of the job in 10 min
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Note that I can write the equation like this:
{{{ (2/3) / 10 + ( 1/3 ) / 10 = 1/10 }}}