Which should be calculated first to solve this story problem? marta has had a health club membership for 5 weeks. she goes to the health club 6 times a week. she exercises for 1.5 hours each visit. she spends 0.75 hours on the exercise machines and the rest of the time she spends swimming. how much time does marta spend swimming in a week? a. the total number of hours marta spends on the exercise machines each month b. the total number of times marta spent exercising in 5 weeks c. the total number of hours marta spends swimming each visit