How many items are in the event “exactly one tail” when a coin is flipped 3 times
When a coin is flipped three times, there are 8 possible outcomes. These outcomes can be represented by the sample space: {HHH, HHT, HTH, THH, HTT, THT, TTH, TTT} where H represents a head outcome and T represents a tail outcome.
To find the number of items in the event "exactly one tail," we count the outcomes that have exactly one tail. There are three outcomes that have exactly one tail: {HTT, THT, TTH}.
Therefore, there are 3 items in the event "exactly one tail" when a coin is flipped three times.