R varies directly as s. Find r when s=10 and k=4

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?

Brad earns $12.75/hr and works 40 hours a week. what is his gross annual income?

Jamie has 7/10 of a pound of chicken to cook for dinner if she's going to put the chicken in between three people how much chicken will each person get