Kayla's target heart rate zone is 142bpm—179bpm. tia's target heart rate zone is 150bpm—183bpm. they stop cycling and take their pulse, and both count the heart rate at 175bpm. if they decrease their heart rates by 20bpm, who will be in her thr zone?
kayla only
tia only
both kayla and tia
neither kayla nor tia

Given that 175bpm will be decreased by 20bpm, this will make both heart rate count of Kayla and Tia to 155bpm. Since Kayla's target heart rate was 142bpm-179bpm and Tia's target heart rate was 150bpm-183bpm, this makes 155bpm within their THR zone. Therefore, Both Kayla and Tia are in their target heart rate zone.