Geometry

Question Analysis
This problem demonstrates conditional probability with simple coin flips.
The main focus is understanding how a condition affects the probability space.

Key Concept Explanation
Possible Outcomes: HH, HT, TH, TT
Given Condition: At least one H (excludes TT)
Favorable Outcome: HH

Step-by-Step Solution
Original possible outcomes: HH, HT, TH, TT
With condition (at least one H): HH, HT, TH
Probability both H = 1 favorable / 3 possible = 1...