Final answer:
If you have 5 QRS complexes in a 3-second strip, the heart rate is approximately 100 bpm.
Step-by-step explanation:
The heart rate (HR) can be calculated by determining the number of beats per minute (bpm). In this case, if you have 5 QRS (ventricular contraction) complexes in a 3-second strip, you need to adjust the time per beat to find the HR. To do this, divide the total time (3 seconds) by the number of QRS complexes (5). This gives us 0.6 seconds per beat.
To convert this to beats per minute, we need to find the reciprocal of the time per beat. The reciprocal of 0.6 seconds gives a value of 1.67 beats per second. To convert this to bpm, multiply by 60 (seconds in a minute), which gives us approximately 100 bpm.
Therefore, the answer is Option C: 100 bpm.