There are two main ways you could write this. You could write 2.7 bps (beats per second).
You could write it as 162 BPM. That's 162 beats per minute. That's a standard way to track heart beat.
Either would be a unit rate.
162 heartbeats/ 60 seconds = 2.7 heartbeats per second
162/60 = 2.7
2.7 beats per seconds
162 heartbeats in 60 seconds as a unit rate.
divide 162 by 60 =
so 2.7 beats per seconds ot 162 beats per minute