<PRE><B>Question 1086523</B>
RATES, J, B, D, in JOBS/HOUR

{{{system(J+B=1/2,B+D=1/3,J+D=1/4)}}}

{{{J+B+B+D+J+D=1/2+1/3+1/4}}}

{{{2J+2B+2D=6/12+4/12+3/12}}}

{{{2(J+B+D)=13/12}}}

{{{J+B+D=13/24}}}---------combined rate,  {{{13/24}}} {{{jobs/hour}}}


Combined TIME for the three together to do 1 job:
{{{24/13}}} hours;

--
1.846 hours
OR
1 hour 51 minutes</PRE>