Try these. Although the answers will be the same, try the 300 and 1500 method
1.
2.
3.
1. Heart rate is: Counting complexes 60. 300/5 or 1500/25
2. Heart rate is: Counting complexes 30 300/10 or 1500/50
3. Heart rate is: Counting complexes 90, 1500/18 is 83