Question 425168
Let {{{t}}} = my time to do job alone in hours
In words:
(1 table)/(4 hrs) + (1 table)/(t hrs) = (1 table)/(3 hrs)
{{{ 1/4 + 1/t = 1/3 }}}
Multiply both sides by {{{12t}}}
{{{ 3t + 12 = 4t }}}
{{{ t = 12 }}}
I take 12 hrs to complete job working alone
check answer:
{{{ 1/4 + 1/t = 1/3 }}}
{{{ 1/4 + 1/12 = 1/3 }}}
{{{ 3/12 + 1/12 = 4/12}}}
{{{4/12 = 4/12}}}
OK