The following graph gives the heart rate of a woman before, during, and after an aerobic workout. Use it to answer the problem. Heart Rate (beats/min) 160 140 120 100 W 80 60 40 20 -10 10 20 20 A Time 30 30 40 50 60 (min) 13 W: Warming up, T: Training, C: Cooling down (a) What was her heart rate before beginning the workout? beats/min (b) After beginning her workout, how long did it take the woman to reach her training-zone heart rate? min