You mean like the tricuspid and mitral (bicuspid) valves?
Answer:
3/8
Step-by-step explanation:
The possible outcomes
TTT TTH THT THH HHH HHT HTH HTT = 8 outcomes
There are TTH THT HTT 3 with exactly two tails
P ( exactly 2 tails) = 3/8
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divide the numerator and denominator by 13
=