1. The problem statement, all variables and given/known data 2. Relevant equations ΔU = Uf - Ui ΔW=-ΔU 3. The attempt at a solution I am unsure if the question combines both climbers' masses or they each have a mass of 75 kg + the 20 kg they are holding. In a), are they asking for the total work of each climber? Or just the gravitational potential energy? For b), do you also just find the gravitational PE at each camp stop?