You can do one-half of a job in you can do one half of a job in a an hour. Your friend can do one-third of the same job in an hout How long will take to do the job if you work together? te your answer as a decimal

Ben frank is an electrician who installs lighting fixtures. he charges (in dollars) his clients 15h+40f15h+40f where hh is the number of hours worked and ff is the number of fixtures installed. how much does ben frank charge when he works 77 hours and installs 99 fixtures?