Question 1207487
Normally, 8 men work for 12 days to do 1 job.
r, work rate for 1 man
{{{8r*12=1}}}


Work done described, 
8 men for 3 days and then 8+6=14 men for some unknown x more days to finish 1 job;
{{{(8r)(3)+(14)r*(x)=1}}}
{{{24r+14rx=1}}}
{{{24(1/8)(1/12)+14(1/8)(1/12)x=1}}}
{{{1/4+(7/4)(1/12)x=1}}}

{{{1+7x/12=4}}}
{{{7x/12=3}}}
{{{x=3(12/7)}}}
{{{highlight(x)=36/7=highlight(5&1/7)}}}




-------------below contains arithmetic mistake-----------------
{{{1+7x/3=4}}}

{{{7x/3=3}}}

{{{cross(x=9/7)}}}------ <s>a little over a day with the extra six men to finish</s>