Mathematics for IGCSE & O level - Probability (Section 5 - No. 45)

A weather forecaster says there is a 70% chance of rain. What are the odds of it *not* raining (in fractional form)?

7/10

3/10

7/3

3/7

If the chance of rain is 70%, the chance of no rain is 30%, which is 30/100 = 3/10.