PCA (Prometheus Certified Associate) sample exam question with answer 269

Question:
Which statement is true about the rate/irate functions?

1. rate() calculates average rate over entire interval, irate() calculates the rate only between the last two datapoints in an interval
2. irate() calculates average rate over entire interval, rate() calculates the rate only between the last two datapoints in an interval
3. rate() and irate() operate in the same exact way
4. rate() calculates rate by using the first two datapoints over an interval, irate() calculates the rate only between the last two datapoints in an interval

Answer:
A - correct answer