Question 1119779
Sally can finish {{{1/6}}} of the job in a hour,her dad can finish {{{1/4}}} of the job in a hour, and Dennis can finish {{{-(1/8)}}} of the job in a hour. {{{1/6+1/4-1/8=4/24+6/24-3/24=7/24}}}

{{{1/(7/24)=24/7}}} It will take them {{{3&3/7}}} hours to finish the job,if they can get Dennis to stop playing when they are finished.