The calculations for finding number of ideal stages, the minimum reflux ratio, and the minimum number of stages are discussed in this video lecture.
Links to my earlier videos related to the present topic-
Distillation Part 29- Steps involved in the McCabe-Thiele Method
https://youtu.be/tEW5ySuFKX8
Distillation Part 32: Distillation under total reflux
https://youtu.be/xHLesI6GTOA
Distillation Part 33: Minimum Reflux Ratio
https://youtu.be/8R0iZ_6jMaY