For Probability:
Total Desired Outcome / Total Possible Outcome = Probability
Tips:
1. Be careful with terms like “or” & “and”.
2. Probability of anything will never exceed 1.
Some tips on “Probability”:
Video on “ Concept, Shortcuts & Tricks and Practice Problems of Probability”
To know more about this topic, go to the below link:
GMAT Club - Probability