The probability of getting exactly two tails.
E = {HTT, THT, TTH} and S = {HHH, HHT, HTH, HTT, THH, THT, TTH, TTT}
(Apply formula: )
The probability of the experiment is .
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
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(Apply formula: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=6d73426249881c5f27a07669b150cb63.png\")
)![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=e44a5207e9232c8f69e666179e9222d4.png\")
.