Norder to achieve maximum results from aerobic exercise, one should maintain one's heart rate at a certain level. a 45-yr-old woman with a resting heart rate of 75 beats per minute should keep her heart rate between 135 and 155 beats per minute while exercising. she checks her pulse for 10 sec while exercising. what should the number of beats be?

between 22 an 25 beats

Explanation:

If this lady need to present a heart rate between 135 and 155 beats per minute while she is exercising.

To calculate the beats in 10 sec, is with a simple rule of 3:

If in 60 sec = 135 beats

       10 sec =    x                                            X= (10 x 135)/60 = 22 beats

And then calculate the higher range

If in 60 sec = 155 beats

       10 sec =     x                                        x = (10 x 155)/60 = 25 beats