When a quarter is tossed four times, 16 outcomes are possible.
hhht hhth hhtt hthh htht htth httt thhh thht thth thtt tthh ttht ttth
here, for example, htth represents the outcome that the first toss is heads, the next two tosses are tails, and the fourth toss is heads. list the outcomes that comprise the event of tossing exactly three tails.