The average resting heart rate for an adult is typically between 60 and 100 beats per minute. To convert this to beats per second, you can divide the beats per minute by 60.
- 60 beats per minute = 1 beat per second
- 100 beats per minute = \( \frac{100}{60} \approx 1.67 \) beats per second
Therefore, the average number of heartbeats per second for a resting adult is generally between 1 and about 1.67 beats per second.
Among the options you provided, 1 1/2 beats per second (which is 1.5 beats per second) falls within this range and is a reasonable average.