Mr. Walker ask her students if the question 3/5÷415 equals 9/4 is true is the question true and which statement could student used to check the equation

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?