In a 15-minute interval, there is a 20% probability of seeing at least one shooting star. What is the proba­bility that you will see at least one shooting star in one hour?

The probability of not seeing one shooting star in 15 minutes is
= 1 – P( One shooting star )
= 1 – 0.2 = 0.8 (20% probability, hence, 0.2)

The probability of not seeing any shooting star in an hour:
(0.8) ^ 4 = 0.4096

The probability of seeing one shooting star in an hour
= 1 – P( Not seeing any star )
= 1 – 0.4096 = 0.5904

Ans: 0.5904